Manual of Military Engineering (1905)

8/8/2019 Manual of Military Engineering (1905)

http://slidepdf.com/reader/full/manual-of-military-engineering-1905 1/331



MILITARY BOOKS.

PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE.

Aud to be purchased, either directly or through any Bookseller, i

WYMAN AND SONS, Ltd., Fetter Lane, E.C, ; or

OLIVIER AND BOYD, Edixbukgh; or

E. PONSONBY, 116, Gkaftox Street. Dublin.

ARMY REGULATIONS:—PAY, APPOINTMENT, PROMOTION, AND NON-EFFECTIVE

PAY OF TfTE AEMY. RovalWarrant. 1900. Price Is (Out of print.)

ALLOWANCES OF THE ARMY. Regns.1003. Price Is.

CLOTHING OF THE ARMY. Regms. Pait I. Eegular Forces.

1904. Price Is. Part II. Militia. 1904. Price 6d.

DRESS REGNS. FOR OFFICERS OF THE ARMY (including the

Militia). 1904. Price a?. 6d."

EaniPMENT OF THE ARMY. Regns. Part 1. 1902. Price I5.

Part 2. Details :—Sections—I. Infantry. 1904. Price id. II. Cavalry. 1905.

Price 6d. III. Army Service Corps. 1904. Price 3d. IV. and IVa. ArmyOrdnance Corps. Army Pay Corps. 1904. Price 2d. V. Army Medical

Corps. 1903. Price 2d. VI.-IX. Colleges and Prisons. 1898. Price 2(f.

VIIC. Training Schools Depot, B.A.M.C. 1902. Price 2d. X. Engineers.

1902. Price 6d. XI. (a) Horse Artillery, with B.L. 12-pr. 6 cwt. 1904.

Price Qi. (b) Field Artillery, -with Q.F. IS-pr. 1904. Price 6d. (c) Field

Artillery, with B.L. 15-pr. 1904. Price 6i. (d) Field Artillery, with B.L.

5-inch Howitzer. 1904. Price Qd. (e) Horse and Field Artillery Staff and

Dep6ts, with 12-pr. 6 cwt. and B.L. 15-pr. 1904. Price 6c?. Xlla. GarrisonArtillery. Price 2s. <od. XIIc. Heavy Artillery Brigade. 1905. Price &d.

XIII. Staff Units in Time of War. Price 2d. XIV. and XV. Eemount Depotat Base. Mounted and Dismounted Company of Signallers in Time of War.1904. Price 2d. XVI. Militia. 1905. ^rice 6d. XVII. Yeomanry. 1903.

Price Qd. XVIII. Volunteers. 1905. Price 6rf.

EaUiPMENT. INSTRUCTIONS FOR FITTING ANDWEARIXG BANDOLIER, Patte-n ] 90.3. Price 2^;.

KING'S REGNS. AND ORDERS FOR THE ARMY. Proyi.sional

Edition. 1904. Price 1.?. (od.

MILITIA REGNS. (Provisional.) 1904. Price Is.

ORDNANCE COLLEGE REGNS. 1904. Price Is. 6d.

ORDNANCE SERVICES. ARMY. Reg-ns. (Provisional.) 1904.

RECRTJITING FOR THE REGULAR ARMY, MILITIA, ANDI -vrPERIAL YEOMANRY. Regns. for. 190::;. Price 6'i.

VETERINARY SERVICES. ARMY. Reg-ns. 1900. Price 6d.

ARMY SERVICE CORPS:—TRAINING. rProvisional.) 1903. Price 1«.

STANDING ORDERS. 1895. Price Is. 6d.

SUPPLY. HANDBOOK FOR. Price Is, 6d.

ARMY ORDERS. General Orders, Reg-ulations, and Instructions

promulL'ated to the Army. Monthly. Price 3'.?. Covers for ditto. Price sV.

WAR OFFICE LIST. 1903. Sold by Harrison 4- Sons, 59, Pall Mall, S. W.Pric .->s. ?!?'.

ARMOURERS. Instructions for. 1904. Price Is. Bd.

CAVALRY TRAINING. (Provisional.) 1904. Price 1*-.

YEOMANRY. IMPERIAL. TRAINING. 1905. Inptmctions. Priceli.

Do. Do. REGULATIONS. 1903. Price Is.

OVt. 11464 35,000 9 |05—II & S 5l'^'.t)



MILITARY BOOKS, published by ^M^.ôrity—continued.

BICYCLES. Care and Preservation of. 1905. Price Id.

CYCIilST TRAINING. (Provisional.) 1902. Price 2fZ.

ARTILLERY TRAINING :-

FIELD. 1904. Price Is.

GARRISON. Vol. I. 1902. Price 6c?. Vol. II. 1904. Price 6(f.

(Proviiional.) Vol. III. 1905. Price Is.

HEAVY. (Provisional.) 1904. Price 6dSIEGE 1901. Price 9d

ARTILLERY. FIELD. Tactics of. 1897. Price Is.

ARTILLERY. MUSEUM. In the Rotunda, Woolwicli. Catalogue

of. 1889. Price Is. 9rf.

ARTILLERY KIT PLATES. Nos. 1 to 10. Price 2J. each.

ARTILLERY AND RIFLE RANGES ACT, 1865. Bye-laws made byHer Majestj^'s Principal Secretary of State for the War Department, with the

consent of the Board of Trade. 8vo. Price \d. each :—

Aldeburgh. Ash, Aldershot Camp. Hj'the. Inchkeith Battery. Kinf^hornes?.

Landguard. Finborough. Lydd. Middlewick. Millbrook. Orchard Portman

(1897). Paull Point Battery, Salisbury Plain (price Mi.). Scarborouf(li (189.^).

Scarborough Artillery (1902). Scraps Gate. Shoeburyness. Southwold,

Strensall. Warden Point Battery and Hurst Castle. Wash. Whitehaven

Batt«ry. Cumberland.ARTILLEAY. ROYAL REGIMENT OF. Standing Orders of the.

Nove.-nbpr, 1893. Price 2s.

ARTILLERY STORE ACCOUNTS. Notes on. Price 6c?.

ELECTRICITY. Notes on. For the use of the Garrison Artillery. ByLt.-Col. .1. R. J. JoCKLYW, R.A. Price Is. U.

ENGINEER SERVICES. Regns. for. 1900. Price Is. 6c?.

ENGINEERING. MILITARY. Instrviction in. Compiled at the

School of Military Engineering, Chatham. Svo. Cloth.

Part 1.—Field Defences. Seventh Edition. 1902. Price Is. 6cZ.

Part 2.—Attack of Fortresses. Fifth Edition. 1896. Price Is. .3q!.

Part 3.—Military Bridging and Use of Spars. Fourth Edition. Corrected to

January, 1902. Price Is. 6rf.

Part 4.—Mining and Demolition. Fifth Edition. 1901. Price Is. 6rf.

Part 5.—Miicellaneous. Fifth Edition. Price Is. M.Part 6.—Military Railways. Price 4<r.

ENGINEERING. "MILITARY. Manual. (Provisional.^ 1903. Price Is.

ENGINEERS. FIELD. DriU. 1899. Price 2s.

ESTABLISHMENTS. WAR. Sees. 1 to 4, 6, and 7. 1905. Price \d. each.

EXPLOSIVES. SERVICe. Treatise on. 1900. Price Is. 6cf.

FIELD SERVICE REGULATIONS :—Part I—COMBINED TRAINING. 1905. Price Is.

Part II.—"WAR ADMINISTRATION. 1905. {Jn vrepnration.^

FIELD SKETCHING AND RECONNAISSANCE. Manual of.

Price Is. 6a:.

FORTIFICATION AND MILITARY ENGINEERING. TextBook. Part II. (1894.^ Price 6s.

HORSE AND STABLE MANAGEMENT. Manual. 1904. Pricp Ad.

HYDRAULICS FOR GARRISON ARTILLERY. Manual. 18j5.Pricei 4.*. (V/.

INFANTRY. Drum and Flute Duty. 1887. Price 2s.

INFANTRY TRAINING. 1905. Price Is.

INFANTRY. MOUNTED. TRAINING. 1904. (Pro^/i^îonal.) Price 6J.

INTELLIGENCE DUTIES IN THE FIELD. Regrns. for. 1901.

Price '2d.

RIFLE RANGES. Miniature and Safety. Instructions for. Price 3c?.

Do. Do. Care and Construction of. Do. Price Sd.

MILITIA. Regns. for. 1904. (Provisional.) Price Is.

MUSKETRY REGNS. 1905. Price Is.

MUSKETRY EXERCISES. (Provisional.) 1904. Price 3d.

ORDNANCE CORPS. ARMY. Standin^^ Orders. 190'^. Price 6d.

ORDNANCE SERVICES. ARMY. P.eg-r'?. for. IS.^02. Price Is.

ORDNANCE. SERVICE. Treatise on. 6th Edition. 1904. Price 10s.



MlLITAItV BOOKS, f'tiblixhed by AuthoriUj—cowWnnÂ.

PROJECTION. -Linear Perspective. Text Book for R.M. Academy.Ill two pfirts. Price H.c.

RAILWAYS DURING THE WAR IN SOUTH AFRICA, 18t 9-1902.Price 4.*.

VOLUNTEER CORPS. Purchase of Land by. 1803. Price Id.

VOLUNTEER FORCE. Regns. for. 19ul. Amended to July, 1904.

Price Is.

VOLUNTEERS IN BRIGADE AND REGIMENTAL CAMPS,Oli WHEN ENCAMPED WITH THE REGULAR FOKCES. Orders andInstructions for. Revised M;-.v, \%^2. Price \d.

STEAM ENGINES AND BOILERS. Notes on the Management of.

l-^^fl. Price 1(Z.

DERRICKS, SHEERS, AND HOiDFASTS. 1898. Price 9rf.

TRUMPET AND BUGLE SOUNDS FOR THE ARMY. 1903.

Price Is.

GUNNERY. Text Book of. 1902. Price 3«.

GUNNERY TABLES. Collected and Compiled by Major G. Mackixlay,R A., for the Text Book of Gunnery, 1887. 48 pp. Price 2s. CcZ.

GUNS. Handbooks for, viz. :—«1-PR. R.M.L. of 64 cwt. (Marks I., II., III.) Land Service.

1900. Price Is. M.,, Converted, of 58 and 71 cwt. 1902. Price 9d,,

of 32 and 35 cwt. 1899. Price U. '

R.B.L. of 16 cwt., on Travelling: Carriag-e. (MovableArmament and Volunteer Batteries of Position.) 1898. Price Is.

16-PR. R.M.L. of 12 cwt. 1903. Price Is.

B.L. (Mark I.) (Field Batteries.) 1904. Price 1«.

,, (Marks II.—IV.) and Carriage Wagon and Limber.(iMark IV.) Field Batteries. 1004. Price Is. ^d.

R.M.L, of 8 cwt. (Movable Armament.) 1900. Price \s.

a.F. (Movable Armament.) 1903. Price 9(/.

of 12 cwt. A.Q.F. (Land Service.) 1903. Price Is. 6d.

B.L. (Marks I.—IV.) of 6 cwt., and Carr ês (Marks I.*

and II.). Horse Artillery. 1905. Pricr

Jointed B.L. (Mule Equipment.) 1904. . Is.

Hotcbkiss. a.F. (Land Service.) 190' :e M.(Land Service.) 19< o .. je Gc?.

(Land Service.) I rice Is.

1903. Price 9rf.

(Marks I. and II.) Laud Service. 1904.

Price Is. 6rf.

12-inch B.L. (Laud Service.) 1904. Price 25.

10-inch R'.M.L. 1903. Price 1«. 6d.

10-inch B.L. (Laud Service.) ]904. Price 2«.

9'2-inch (Land Service.) 1902. Price 2s. ^d.

8-inch R.M.L. Howitzer of 70 cwt. For Movable Armaments andArmaments of Works. Land Service. 1901. Price 2s.

Q,.F. (Land Service.) 1903. Price Is.

B.L. and B.L.C. Land Service. 1904. Price Is. 6rf.

B.L. Howitzer of 30 cwt. (Mark I.) 1904. Price Is.

,, Howitzer of 26 cwt. (Mark I.) Price 3s.

5-4-inch B.L. Howitzer. (Mark I.) 1902. Price Is. 6(7.

5-inch B.L. Howitzer. 1903. Price Is.

5-inch ,, (Marks I.—V.) (Land Service.) 1904. Pr>e 9c/.

4-7-inch a.F. (Fixed Armaments.) Land Service. 1904. Price Is.

4-7-inch Q.F.B. (Mark IV.*) on Travelling Carriage. LandService. 1904. Price Is.

4-inch B.L. (Marks V. and VI.) (Land Service.) 1904. Price Is.

2-9!i-inch Q.JT. Mountain Gun. (Mark I.) Mule Equipment.1901. Price 'M.

0-303-inch and -SOS-inch Converted Maxim Ma ine Gun.(Magazine Rifle Chamber.) 1903. Price \s.

64-PR.40-PR.20-PR.

15-F«.15-PR.

13-PR.121-PR.12-PR.12-PR.

10-PR.6-PR.3-PR. Hotchkiss. a.F.6-PR. Nordenfelt. a.F.3-PR. Nordenfelt. a.F.12-5-inch K.M.L. 38 ton.

6-inch6-inch6-inch

6-inch



[All Rights Reserved.

40

W.O.

MANUAL

OF

MILITAET EMlNEEIll]\Tx

GENERAL ST^FF, AVAR OFFICE.

LONDON :

FEINTED FOR HIS MAJESTY'S STATIONERY OFFICE,

BY HAEEISON AND SONS, ST. IMAETIN'S LANE,PEIITTEES TS OEDINAET TO HIS MAJESTY.

And to be purcliased, either directly or through any Bootsellei', fronx

WYMAN AND SONS, Ltd., Fetter Lane, E.G. ; or

OLIYER AND BOYD, EDi>-BTTEaH ; or

^ E. PONSONBY, 116, Geaftox Sireet, Dublin.

1905.

Price One Shillin'j.



4 2dt,^^ ?<

a. '•-"'V^^ sXyJ\j^. L\^ / ^ y r^

(^w^ 35.000 nf^-R^mi^^_^ ^, ^.,^ ^



'^^-^

^'T^ManuaMs issued

by comnandoTSSe^my Councilfor the guidance of all concerned.

--ico^fUzM^

War Office,

8/A August, 1905.

(5289) A 2



CONTENTS

Chapter. Subject. Page.

I.

IT.

ITT.

IT.

y.

YI.YILVIII.

IX.

X.

XI.

XII.

XIII.

XIV.XV.XVI.XVII.

XVIII.

XIX.XX.

XXI.

XXTI.XXIII.

PAET I.

Peeltaitnabt

ElELD GeOMETUT . .

lNTRE>^CHiyG^ T03LS

WoEKiNG Parties and Execution of In-

trench5ients

Materials .

Retetiments.

Clearing the Foreground

Improvement of existing Coyer, Stockades,

&c. ..

Earthworks. .

Obstacles

Defence of Posts, Villages and Camps

Temporary Eoads ....Knotting AND Lashings..

Military Bridges. .

Camping Arrangements..Hasty Demolitions with Explosives.,

„ Demolition of Railways and Tele-

graphs without Explosives

PART II.

Strength of Materials and Buoyancy

Blocks and Tackles—Use of Spaiis ..

Erame and Cantilever Bridges, Framed

Trestles, Suspension Bridges, and Cask

Piers

Demolition Eoemulje and Working PartyTable, &c.

Roads—Boning and Levelling

Railways and Telegraphs

G-LOSSARY OF TeRMS

Index

5

10

12

14

17

2325

26

31

41

44

51

52

55

68

78

96

101

107

109

lis

]2S

l;{7

]40



MMUAL OF MILITARY ENGINEERING.

(^Tliis book is divided into two parts. Officers should he

ihoroughly acquainted with the matter dealt icith in Fart I.

Part II contains information useful for reference.

The types of the various works described will vary according to

the conditions of time, labour, and material.

Officers and Non-commissioned Officers in charge of luorks

should, while bearing the principles in mind, learn to modify the

types according to local conditions.')

CHAPTER I.—PRELIMINARY.

{See also " Combined Training," 1905, Section 123, and

following sections.)

1. The object of fortification is to strengthen ground, and by Objects o!

thus economising the numbers of the defenders, to swell the fortifica-

force available for offensive movements, by which alone^^°^'

decisive results can be obtained. This object is secured by

fulfilling, as far as possible, the following conditions :

(a) The position to be defended must be chosen with due General

regard to tactical requirements, and with a view Pîiiciples.

to economising men; its strong and weak points

must be carefully studied.

(6) The enemy in attacking should be exposed as muchas possible to the fire of the defenders during the

advance. To this end the foreground may require

more or less clearing,

(c) Every endeavour must be made to deceive the enemy

as to the strength and dispositions of the troops in

the defence, and as to the character of the defensive

works.



6 CHAPTER I.—PRELIMINARY.

(d) The defenders should be sheltered from the enemy's

fire,

andas far as

possible screened fromliis

view,by natural or artificial cover, so arranged as to permit

the greatest possible development of rifle fire.

(e) The free movement of the attacking troops should

be hindered by leaving or creating obstacles to detain

them under fire or to break their order of attack.

(/) The free movement of the defenders should be assisted

by improving communications within their position,

and clearing the way for counter attack.

Shortly stated these principles in order of importance are :

(a) Choice of ground.

(b) Clearance of foreground,

(c) Concealment.

{d) Provision of cover.

(e) Creation of obstacles.

(/) Improvement of communications.

The above are dealt with in detail in subsequent chapters.

2. A thorough knowledge of the fire effect of all arms is

necessary, in order to design good defence Avorks,

Rifle fire, 3, Modern military rifles are sighted to about 2,800 yards.

The slope of descent of the bullet varies from about -^^ at

1,000 yards to

ât 2,800 yards.

Height oi: The heights over which an average man can fire on level

line of ground are :

^^^'

Lying down 1' 0''

Kneeling 3' 0^'

Standing 4' 3'^ to 4' <6"

These heights must be adjusted to suit different men ana

varyinginclinations of ground.



CHAPTER I.—PRELIMINARY.

4. The following table gives the thickness in various materials-

proof against modern rifle bullets at foint blank range :

Material.



s CHAPTER I.—PRELIMINARY.

Field

lio\\ il zerp.

Heavygnis.

Modernaitilleiy.

Ranges.

very large number of fragments wHch are driven in all

directions. They are not so effective as well burst shrapnel.

7. Field howitzers, firing common shell and shrapnel,

havenow been introduced into the service of most nations. They

are light pieces of artillery, firing comparatively heavy shell,

with low charges at high elevation, and in consequence possess

gocd searching power*

No practicable amount of extemporised cover, except as

in Sec. 73, will keep out a howitzer common shell. The effect

of the burst is very powerful, not merely from the fragments

of the shell, but also from the blast and the fumes of the

explosive; but this effect is very local, and slight cover will

suffice against the splinters.

80 Heavy guns up to 6-inch have been used in the field

and will probably be met with in future. They are long-

ranging, but their searching power is little greater than that of

field guns.

9. The object of modern artillery is to reach the defenders

of a parapet by means of fragments of projectiles burst in the

right position, and not by breeching the parapet with the pro-

jectile itself. An occasional sheU may strike and penetrate

the parapet, but in the case of a shrapnel shell the damage

to the parapet wiU be trifling, while in the case of a howitzer

shell filled with high explosive, the effect will be no worse

on a thin parapet than on a thick one. Thus it is useless to

spend time and labour on making a thick parapet to keep

out the actual shell. Against such fire, concealment is of

greatest importance.

Plate 1 gives some idea of the effect of bursting shells.

10. The following table (taken from " Combined Training,"

1905) gives the various ranges of the different weapons :

Terms applied to

ranges.



riai^, /.

Veiier&Sr^hflm. LJ* Li itio. London."

Opposite pouê S.





CHAPTER I.—PRELIMINARY. 9

The extreme width of the area of ground struck by the

bullets of an effective shrapnel is about 25 yards.

The limit of the forward effect of shrapnel at effective range

is about 300 yards.

The radius of the explosion of a high explosive shell is

about 25 yards.

11. The follo^ving terms are used with reference to artillery Matures

and rifle fire :— of îre-

High Angle Fire.—Fire from guns and howitzers at all

angles of elevation exceeding 25°.

Frontal Fire.—When the line of fire is perpendicular to the

front of the target.

Oblique Fire.—AVhen the line of fire is inclined to the front

of the target.

Enfilade Fire.—Fire which sweeps a line of troops or

defences from a flank.

Reverse Fire.—When the rear instead of the front of the

target is fired at.



10

CHAPTER II.—FIELD GEOMETRY.

12. Before proceeding to the more technical portion of

military engineering, it is as well to understand some of the

simplest applications of geometry to the laying out of field

defences.

Slopes. Slopes are usually described by fractions, in which the

numerator expresses the height, and the denominator the base

of the slope.

Thus, in Fig. 2, Pi. 2, the vertical height, B C, is jr of the

horizontal distance, A B. The slope A C would, therefore, be

called a slope of ^ (verbally, one in six).

In Fig. 1, the vertical height B C is four times as great as the

horizontal distance A B. The slope A C is called -i (verbally,

four in one, or four over one).

Slopes are sometimes expressed in degrees. A good rough

rule for converting degrees of slopes into fractions, or the

reverse, is to divide 60 by the number of degrees expressing the

slope, the result gives the denominator of the fraction whose

numerator is 1, e.g., 5^ slope = î^"' ^^ 1 ^^ ^- slope.

N.B.

—This formula should not be used for slopes steeper

than 30^

To lay out 13. To lay out a right angle. Let X be a point in a given

a right straight line A B (Fig. 3), from which it is required to set oS a*"gl^-

right angle.

Take any point C in A B, and drive in pickets at C and X.

Take any convenient length of tape C D X, and make loops

at either end, and find its centre D by doubling it. Xow place

the two loops over C and X and stretch the tape taut into the

position C D X. Take D X off the picket at X and turn it

round till it comes into the position D E, in prolongation of

C D. Join E X, which gives the right angle required.

2nd Method.—From X measure off a distance of 4 units

X C along A B (Fig. 4). Take a piece of line or tape 8 units

long, and apply one end to the point X, and the other to the

point C ; find a point in the tape 3 units from X, and seizing

it at this point, draw the bight out to D, till the line is taught,

then C X D is a right angle. This method is founded on the



I^lajt€> Z,

c Field Geometry .

A C

J^ff.5.[

^x ^^ ^

c :b

-'C SB

^.osW«J{f r * Gr«h«m. Lr* Litho. LoiMlon.





CHAPTER II.—FIELD GEOMETRY. 11

fact that in any triangle whose sides are in proportion of

3, 4 and 5, the angle contained between the two shorter sides

is a right angle.

14. To trace a perpendicular to a given hne from a point To trace

outside. Let X be the point outside the line A B (Fig. 5),perpendi-

from which it is required to draw a perpendicular to that line. ^[^^"^

Take a tape or cord longer than the perpendicular will be ; fix outside a

one end at X, and stretching it taut, swing it round so that the given line,

other end shall cut A B in C. Drive in a peg at C, find D, the

middle point of C X. With D as centre, swing D X or D C

round to the position D E, cutting A B in E. Join X E, then

X E is at right angles to xV B.

15. To lay off an angle of 60"^ or 120^. Let X be the point To lay ofe

in the line A B (Fig. 6) from which it is required to lay off an angles of^

angle of 60°. Take any point C in A B at a convenient distanceo^'lÔ .

from X, and towards that end of the line from which the angle

of 60° is desired to be drawn. Take a tape or cord twice the

length of X C, and fasten the ends to X and C. Seize it by the

middle point and draw the bight out taut to E. Then the

angle

E X Cis 60°

and A X Eis 120°.

16. To bisect a given angle. Let A B C be the angle which To bisect

it is required to bisect (Fig. 7). On B A and B C, mark points ^^'^J^^

D and E at equal distances from B. Find by means of a^^^ ®'

tape or cord a point F equidistant from D and E. Join B F.

Then B F bisects the angle A B C.

17. To lay out an angle equal to a given angle. LetX be the To lay out

point in the straight line A B (Fig. 8), from which it is desired ^^ ^^§1®

to lay off an angle equal to the angle DEC. Fix the points ^^^^*^

D and C at any convenient distance from E, and from the an't^le.

point X measure X G, equal to E C. Then from the point Xas centre, and a distance equal to E D as radius, and from the

point G as centre, and a distance equal to C D as radius,

describe arcs, intersecting at F. Join X F. The angle F X Gis equal to the given angle DEC.

18. To find the distance between any two points A and B Tofmdtbe

when it cannot be measured directly. From B (Fig. 9) lay off(distance

the line B D at any convenient angle, D being at any con-

^^tTwo



12 CHAPTER III. INTPvEInCHIXG TOOLS.

points

when it

cannot be

measured

directly.

vcnient distance. In B D select a point C so that B C is somemultiple of C D. From D lay off the angle B D F equal to the

angle A B D, and on the opposite side of the line B D. MakeD E of such a length that the point E is in line vs-ith A and C.

Then A B : B C : : D E : C D,

BC X DEor AB

CDas shown in PI. 2.

CHAPTER III.—IXTREXCHING TOOLS.

Tools

Use of

tools.

19. The service intrenching and cutting tools are shown on

Plates 3 and 4. It is well to note the dimensions, as

they are useful in laying out and executing work.

A heavy pick with an 8-lb. head has been sealed, and can be

obtained from Ordnance Store if heav3' work is expected.

Only a smaU proportion of spades are carried, as they

are of little use in the field. They are employed for cut-

ting sods, and for digging generally when a pick-axe is not

required.

20. For safety the pick must be used working front and rear,

and never sideways.

Before striking the pick into the ground it should be raised

well above the head with both hands. In bringing it do^vn, the

helve should slide through the hand nearest to the head, and

the weight of the pick should be employed to help in the work.

The shovel is used right or left handed. Xav\Tes make

gTeat use of the thigh in thrusting the shovel under the loosened

earth.

In throwing earth from the shovel there should be no

jerk, the left (or right) hand mûst be allowed to slide freely

up the handle, otherwise the earth will scatter.



J^ta-teS

Intrenching Tools

*3*

'^ 1

Ft^.i.

SpoudUMf^ni 5Ujs Woxs. K ;^

Fs.5.

Crowhar 1a Ihs

S- 6'

05 Wel'trr & Grflhdti L'f LirfÔ London





FLr.t^ 4-

CuTT! NG Tools

Aj-e. FeZUri.g , wer-ffh^ 6li^ 7oxs.

2^:5

BUI Nook

^2.7^^«°^-zn.4!/ 7re^s

Ivff 6 .

Gre<it/ Anver-icarv Croas-cut^Scm weiglU Olbs. loxs.

fhk.

•'

liitjrfi

^-^nuwfwu./iJ;:^.,^

50IT

Wcller & Graham. Lr^ Litha London.

7b foll^tvplcLU3.





CHAPTER III.—INTRENCHING TOOLS. 13

The following tools will probablv bo carried in the field Tntrench-

bv remmental transport, but see Field Service Manuals :— "''? ^°^^^ ^

cutting

tools.



u

Reliefs.

Tasks.

Detail of

working

parties.

Size of

tasks.

Balancingparapet

and ex-

cavations.

CHAPTER IV.—WORKING PARTIES AND EXECU-TION OF INTRENCHMENTS.

21. In digging intrenchments for all except the smallest

works, the working parties are not kept continuously at work,

but are changed at intervals, thus dividing the total time into

periods called reliefs. As regards the length of rdiejs a great

deal depends upon the nature of the work, the total time it

will take, and the climate. Also the question must be con-

sidered as to whether the work has to be hurried through, and

whether it can be carried on by night as well as by day. Short

reliefs are best, and as a rule it will be found that a four hours

relief (actual digging) is quite long enough for the infantry

soldier. Six hours reliefs may occasionally be resorted to.

A task is the amount of work a man has to do in one

relief.

Too much pains cannot be taken in the preliminary details

of working parties, so that they may arrive at the site of

their work, ready provided with tools, their tasks clearly

defined, and the men in such formation as will admit of

their ready distribution on the work. Delay and noise is

thus avoided, and the chance of confusion during night

work reduced to a minimum.In ordinary easy soil the average untrained soldier should

excavate with service tools {see Pi. 3, Figs. 1 and 3) 30 cubic

feet in one hour, or 80 cubic feet in a four-hour relief.

If the soil is very easy these rates may be increased, and

vice versa ; in hard stony ground it may be reduced by 50

per cent.

These rates hold up to a maximum horizontal throw of

12 feet, combined with a lift out of a trench 4 feet deep.

22. As the earth required for the parapet of a large field workis obtained from the excavations (ditch and trench), the areas

of the sections across the parapet and excavation must be

roughly balanced.

PI. 5, Fig. 1, gives an example of a section of a parapet

with high command, the successive reliefs (with their tasks)

necessary for the execution of the work being shown.

Figures shown thus [" 36 ] denote the area of the excava-

tion or parapet in square feet.





Plxit4 .5.

BALANCING PARAPET &. EXCAVATION

z±^-A \ «.^

TASKS

I ReJjrj&f' 76 ctcij5rjc feet

u . ,,.-. 7;^ .. .-

3ir 3S% ,, .. „ -.

TASKS

JT— f ,— »>.^^ - ,,— , , --

PROFILING

^r^.^,

Jhterîor- csrss

''////w//////w/Mmmm^,

s/ae .s OS. Wfiier&Grahan.L'* UrhoLoodon

Oppositepa^ tS.



CHAPTER IV.—WORKING PARTIES, ETC. 15

23. Tracing a work consists in laying out so much of its plan Tracing,

on the ground as is necessary to guide the distribution of

the working parties. This may be done by a mark on the

ground, or by tapes.In hasty defence work tracing with a tape is usually only

necessary for night work.

24. When making works of high command, profiles should be Profiling,

put up to guide the construction of the parapet. {See PI. 5.)

For high profiles it is best to drive stout pickets into the

ground at the position of the verticals, construct the profile

bodily to a straight line, lying flat on the ground, and then

up-end it, and nail it to the pickets on a level line.

Profilesare

laidout at

right anglesto the crest line. They

should be placed at intervals of about 30 feet, two at least being

required for each face near the angles.

High profiles should be secured by stays or light guys, or

they are liable to be blown down.

25. For all intrenchments the normal distance apart at Orgauisa.

which the men are spaced for work is two paces (5 feet). ^^^^ 9^

This can be reduced, if necessary, to 4 feet, but it cramps the "^*^ff^"S

diggers.

Task work is better than working for a fixed time.Inarranging tasks it is better to under estimate the men's powers

in order to avoid incomplete tasks.

In arranging reliefs, the following rules should, if possible,

be adhered to :

(1) The second and succeeding reliefs should have less

earth to excavate than the first, as the diggers have

further to throw.

(2) If fossible, each relief should leave a vertical face

of earth for the next relief to commence upon. Forinstance, in PL 5, Fig. 1, the dividing line between

the reliefs is vertical and not horizontal.

26. _A party of the necessary strength for the work in hand. Detailing

including a reserve of one-tenth, having been demanded, working

should be detailed from a company, battalion, brigade, or P^^'^^^s.

division, and not formed of detachments from difierent com-panies and corps.



16 CHAPTER IV.—V/ORKING PARTIES, ETC.

The party is then marched to the tool depot to get their

tools, which should be ready laid out, according to the detail

of the several parties, either in rows or in heaps, the men in

the former casefiling

onthe

rows and taking up a pick inthe left hand and a shovel in the right, or filing between the

heaps and receiving the tools in the same order in passing.

For extending men for work, see " Infantrv Trainiog,'*

1905, p. 96.

If the party be large and the work of a complicated nature,

such as a redoubt, the men should be divided into detachments,

each under a superintendent, corresponding to definite portions

of the work, formed in column at some distance from the site,

and successively extended along the line, driving in their picks

on the left of their tasks, and laying down their shovels along

the front. It is sometimes advisable, in order to save time

in extending, to keep a separate detachment for distributing

on the excavations at the angles.

No work must be commenced till the distribution of the whole

is complete, as it is difficult to remedy mistakes when work has

once begun, the subsequent shifting of men invariably tending

to confusion and possibly loss of tools, clothing and accoutre-

ments.

Double When the men available greatly exceed the tools in number,manning

i^, j^^y be advisable to tell off twô men to each set of tools, and*°

so complete the work in about two-thirds of the ordinary

time.

Superintendents should be relieved at alternate hours to

the working parties, to ensure continuity in work.

When the distance that the earth has to be thrown is too

great for the diggers to deposit it in its final position in one

throw, shovellers wiU be necessary as well as diggers.

Methods 27. Diggers should commence on the left of their tasks, in

of execu- order to incommode each other as little as possible.

tmg tasks.j^ excavating V-shaped ditches the slopes should not be

formed until the last relief, rectangular portions being taken

out first.

If not under fire the earth first excavated should be furthest

thrown.



CHAPTER V.—MATERIALS. 17

In making fire-trenches the men should try to get cover as

soon as possible. Sods and lumps of earth should be used

for revetting the interior slope, which must be made as nearly

vertical as possible, the revetting being carried on with the

parapet.

CHAPTER v.—MATERIALS.

For approximate time required for carrying out work referred to

in this chapter, with labour and tools, see table, p. 120.

28. The materials, which are mostly available for the con- Earth,

struction of field defences are earth, st-- nes, timber and

brushwood, while railway plant, iron sheeting, wire barbed

and plain, &c., may often be obtained. Of these materials

earth is the most valuable as well as the most generally used.

For the purpose of field fortification, earth is usuallypro-

cured from the trenches dug as near as possible to the place

where it is to be used.

The steepest slopes at which thrown-up earth will stand

is about 45° or \.

29. Sods are used for revetments and also to form walls in Sods,

special cases. They should, if possible, be cut from meadowsgrowing thick grass. Each sod should be about 18 inches

long, 9 inches broad (these dimensions depending, however,

on the width of the spade) and 4| inches thick.

30. Stones may be employed to form rough walls in places stones.

where digging is difficult or impossible. A well-built rubble

wall, 12 to 18 inches thick, will keep out bullets, this thickness

being necessary to avoid having any " through " joints.

Two such walls about 10 feet apart afford good protection

against artillery fire, the outer wall, which should be at least

2 feet thick, serving to burst the shell.

31. Timber is used in the construction of bridges, huts, Timber,

splinter-proofs, stockades, abatis, &c.

(5289) B



18 CHAPTER V.—MATERIALS.

Felling 32. The tools employed for felling timber are the felling axe,Timber.

^|^g hand axe, the cross-cut saw and the Jiand saw (PI. 4).

Of these the felling axe in the hands of an experienced work-

man is, probably, the best of all. The hand axe is only

suitable for felling small trees not exceeding 12 inches to

15 inches in diameter, but it may be employed with advan-

tage when men practised in the use of the felling axe are

not available, as it requires little or no skill in handling.

The cross-cut saw or the hand savr may also be used, the latter

with small trees only, provided that measures are taken, bywedging or otherwise, to prevent the weight of the tree from

jamming. Inexperienced men can use the cross-cut saw more

easily and safely than the axe, and can cut more quickly with it.

When convenient, it is best to fell a tree in the direction of its

natural inclination. In using the felling axe, the tree should be

first attacked on the side on which it is required to fall, a rope

being employed, if necessar)-, to pull it over, as, for instance,

when the natural inclination is not in the required direction.

When the tree has been cut into as far as the centre, or a little

beyond it, the workman should change over to the opposite side

and commence cutting about 4 or 5 inches above the former cut

until the tree falls. The cuts should be as shown in Fig. 4,

PL 4, where the arrow indicates the direction in which the

tree is required to fall. With beginners, or when it is not

important to save timber, and when there is no objection

to leaving the cover which high stumps afford, the point a

should be the height of the hip, h c should be about three-fourths

the diameter of the tree.

It may sometimes be convenient to employ both the saw

and the axe to cut down a tree. In such cases the axe should

be used on the side towards which the tree is to fall, and the

saw en the opposite side.

The teeth of all saws used for cutting down timber should

be set wide.

Cutting 33. Brushwood is much used in military engineering for

!!L"!^"roadmaking and revetting purposes, and for the construction

of gabions, fascines, hurdles, &c.

WiUow, birch, ash, Spanish chestnut and hazel are the

most suitable kinds, and work best if cut w^hen the leaf is off.

ood.





Thff^' G.

V

Tiq.Z

or'JBnttorL

Brushwood.

JifeZfvoOi of 7>iftdz7i^^r*itsJuvood

^zy.;. /rj) JJVB

^^.5

4^06 S. 05 .eilerSrGraham. L'* Lirho, London

Opposite pajge J



CHAPTER V.—MATERIALS. ID

As a rough rule it may be taken that 1,000 square yards of

brushwood, years old, make up three G.S. wagon loads.

34. Withes, for binding purposes, in lieu of wire spun yarn, Withes.&c., are made of pliable wood, such as willow and hazel. They

should be 6 feet to 7 feet long, | inch in diameter, and made

pliable by being well twisted, the thin end being placed under

the left foot, and the rod twisted with the hands, avoiding

kinks. If the rod is stiff a smaU. piece of stick, lashed across

the butt, will be of use in twisting it (PL 6).

35. A fascine is a long faggot tightly packed and carefully Fascines,

bound, used in revetments, for foundations of roads in marshy

sites, and for

manyother purposes. The usual dimensions

are 18 feet long and 9 inches in diameter. It is made in a

cradle of trestles placed at a uniform level (PL 7, Figs. 6

and 9). The brushwood, trimmed if possible, is laid in the

cradle, projecting about 1 foot 6 inches beyond the outside

trestles, and adjusted so that there may be no weak place.

Crooked rods must be half sawn through and straightened.

The fascine is then gauged with the choker (Fig. 7), Choker,

which consists of two wooden levers, 4 feet long, connected

at 18 inches from their ends by a chain 4 feet long, provided

with two gauge rings, 28 inches apart, corresponding to the

circumference of the fascine.

To use it, two men, standing one on each side, place the

centre of the chain under the fascine with the short ends of

the levers uppermost, cross the levers to each other over the

fascine with the short ends down, and bear down on the long

ends until the gauge rings meet.

Binding must be commenced at one end. The first binding Binding,

(of we, spun yarn hoops or withes) is put on 3 inches

beyond the outside trestle, and the remainder (12 in all) at

intervals of about 18 inches. This admits of the fascine being

cut, if required, into 9 feet or 6 feet lengths. The ends of the

fascine are sawn off 9 inches beyond the outside bindings.

In all cases the fascine must be choked close up to the

position of the binding while the latter is being put on.

With withes an eye is formed at the tip, the withe put on With

under the fascine, the ends brought up, the butt passed through withes.

the eye, turned back and twisted round itself (Fig. 5).

(5289) -B 2



Piclvets.

Gabions.

Brush-

woodgabion.

20 CHAPTER V.—MATERIALS.

Length.



PlaJte 7

Brushwood.

Fascines

:Fiff.7.

â^'czne. Choicer^,

M-PO->^.

. >,<<!> s^,mf4,.^ ,..> .. .o

WelleriGrahsff'. L" Lirtxi Lerdw



i





Plnte 8

Brusjiwood.Gabions .

S&i/ym' yj'ithj \vir& or' spuny i/oc/yz/

Tiff. /. Tzff.Z.

Tiff. 4^.

jyl ||HI HI

i[H



CHAPTER V.—MATERIALS. 21

The web is constructed by a process called waling, as Waling,

follows :

Three rods well trimmed are placed with their butt endsinside three adjacent pickets (Fig. 1). The first rod is passed

over the other two, outside the two adjacent pickets, and inside

the third, the second and third rods are similarly treated, and

the process continued. When introducing a fresh rod in place

of one that is coming to an end, the two must be laid together

for a few inches and worked as one rod.

The web must be close, even and well pressed down, the

<limensions strictly maintained by frequent gauging, and the

pickets kept upright and in their proper places, otherwise

the gabion will become either crooked or funnel-shaped.

When the web has reached a height of 2 feet 6 inches, Pairing,

two pairing rods are put on as follows :—The rods must be

9 feet long, well twisted (like withes) and pointed at the butt

ends, which are driven down into the web at its lowest point

on either side of one of the pickets, the rods are then passed

alternately over and under each other, and inside and outside

the pickets (being well twisted during the operation), and

finished off and driven down the web on either side of the

picket next beyond that at which the pairing was commenced.

The pairing rods are then sewn down to the web at Sewing,

four equal intervals, either with wire, spun yarn, or withes.

If the latter -are used they should be about 6 feet long and well

twisted. The first sewing is placed where the pairing rods

are double, the butt end is passed through the web from the

outside 7 inches below the top and turned down inside ; the

withe brought over the top, down inside, through the web

above the old place, do^vn outside, through the web again

7 inches lower down, back through the web, clasping the butt

end in passing down outside, back through the web another

7 inches down, and finished off with two half hitches round the

butt end above the clasping.

The gabion is then reversed, pairing rods put on at the bottom

and sewn in four places, the sewings alternating with those

already put on. A carrying picket must then be driven through

the web.

Forked pickets (Fig. 6) driven well down into the web

may sometimes be used instead of sewing.



22 CHAPTER v.— MATERIALS.

Jones'

gabions.

Hurdles.

Willesdtn 39. Willesden paper band gabions are an article of store,

paper Each gabion consists of 10 bands, 3 inches wide, fastened atga ions.

^^^ ^^^^ -^^^ ^^^^^ copper cUps. (Pb 8, Figs. 8 and 9.)

To make it, lay a band ready fastened in the form of a circle

on the ground. Drive the pickets, 10 in number, round it

alternately inside and outside, sHp a second band over the

tops of the pickets, alternating with the first band, and press

it half-way down to keep the pickets steady, until the third

band is on, when they may be pressed down to the bottom,

and the remaining seven bands put on. All the joints should

be kept behind two adjacent pickets. A thin carrying picket

can be driven through the web. The top and bottom bands

should be nailed to the pickets.

Jones' steel band gabions are still articles of store, but no

more will be made. They are made up similarly to Willesden

paper gabions.

40. Hurdles, unless for a special object, are usually made

6 feet long and 2 feet 9 inches high in the web, thus correspond-

ing to the height of a gabion {see PI. 9).

They are useful for revetments, huts and temporary roadways.

A line 6 feet longis

marked on the ground, and dividedinto nine equal parts, and a picket (about 3 feet 6 inches long

and from 1 inch to 2 inches in diameter) driven in at each

division, the two outside ones being somewhat stouter and

longer ; the web is then constructed by randing.

Ranfling. Randing is worked with single rods, and is commenced

in the centre {see Fig. 1). The rod is taken alternate sides of

the pickets, twisted round the end pickets, and woven back

to the centre. A fresh rod must overlap by several pickets

the one which it supplants.

Pairing rods are used in the centre and at both ends of the

web, which is usually se^vn top and bottom in three places.

The operation of slewing is the same as randing, two or

three rods being worked simultaneously ; it makes weaker

work than randing.

Slewing.



JL L4AJL4' y

Brush wood

TiffJ.

CcfTTurve^t^cerfzepvi? ofa^ 6fPHur-clle..

7 to 2/ ISzuTclLe^ o/^.JBr7zs7iAA^6o(L

." OS.

Ojjrposxte page 22-





23

CHAPTER VI.—REVETMENTS.41. A revetment is a retaining wall used for supporting

earth at a steeper slope than that at which it would naturally

stand.

The following are the revetments most in use in the field :

42. Gabion.—This is one of the best that can be used when a Gabion

considerable height of parapet has to be dealt with, but for revetment,

breastworks gabions are extravagant of material. They are

usually placed at a slope of \. This tilt may be obtained by

resting their outer edges on a fascine sunk 3 inches into the

ground (PI. 10, Fig. 1), or in any other way.

For high parapets two fascines are generally interpolated

between the rows of gabions, and in this case it is advisable

to anchor the gabions \\\i\\ wire to stakes, fascines, or logs

buried in the parapet. (Figs. 3 and 1.)

43. Fascines.—Fascines make a poor revetment by themselves, Fasc ne

and their use is generally confined to revetting steps. They ^^ê^ment.

should be well picketed down.

44. Hurdles.—Hurdles form some of the most useful forms of Hurdle

revetment, either in the form of ready-made hurdles, or revetment,

continuous hurdle revetment constructed simultaneously

with the parapet. In either case the slope is built

at \, and frequent anchoring is essential. Stretching of

fastenings, &c., due to weight of earth in the parapet, will

bring the hurdle to a slope of \, as shown in PL 10, Fig. 7.

In continuous hurdlework the web is formed by randing or

slewing, each pair of men having 10 feet or 12 feet of revetment

as their task time, J to | of an hour. They must work in

their rods with the men on either side. (Fig. 7.)

45. Brushwood.—This is a rapidly made and useful revetment. Brush-

Stakes are driven in at a slope of about f , at from 1 foot to wood

2 feet apart, and anchored back. As the parapet rises, looserevetment,

brushwood (or ferns, reeds, straw, &c.) is filled in between

the stakes and the parapet. (Fig. 2.)

46. Sandbag revetment is made at a slope of f with alternate Sandbag

rows of headers and stretchers (the former with the chokes, revetment,

the latter with the seams turned into the parapet), breakingjoint (Fig. 5). The bags must be laid at right angles to the



24 CHAPTER VI.—REVETMENTS.

slojie, .ind not liorizontally or the revetment may slide. Thev

should be not more than about three-quarters full, and shouldbe well beaten when placed in position. Two men build, and

if supplied with sandbags by carriers and fillers, will lay about

70 bags an hour ; 1 cubic \Hird of earth fills about 50 bags.

Sod 47. Sod revetment is built at a slope of |. The sods shouldrevetment.

\^fy ^^^^ jg inches long, 9 inches wide, and not more than i\ inches

thick, with a sharpened spade or sod-cutter (Fig. 8).

They must be laid in alternate rows of headers and stretchers,

grass downwards, breaking joint, and at right angles to the

slope, with two rows of sods in each stretcher course. Thetop layer should be laid with grass upwards, and all headers.

They should be bedded and backed by fine earth well rammed.

For superior work the sods should not exceed 3 inches in

thickness; and a picket should be driven through each sod.

Cleit fir pickets are better than round, which split the sods.

Two builders should lay 70 to 100 sods an hour.

Timber 48. Timber revetment may be made by driving strong stakes

revetment j^^q ^]^g ground, placing planking behind them, and filling in

with earth. The slope wall depend on the strength of thetimber, f will generally be safe. The stakes should be anchored.

Planks should never be used for revetments where they will

be exposed to the fire of high explosive shells.

Willesclen 49. Willesden canvas.—This is kept as an article of store,

canvas[^ \ojig strips about 3 feet wide. For use, stout pickets should

be driven from 12 inches to 18 inches apart and anchored.

The canvas will then be stretched between these and the

parapet, being laced with wire to the pickets top and bottom

at about 6 feet intervals (Fig.6).

Wire 50. Wire netting with stakes passed in and out of the meshesnetting

^j^^j anchored back forms a good revetment in soils which arerevetment. j. , i

not too sandy.

All revetments of parapets intended for musketry fire

should be finished off with one or two courses of sods or sand-

bags, where available.

For estimate of material required for revetments, see table^

p. 120



vuue. ;o.

Revetmep^ts

Brushwooo

OANHBAGS ^'.e: CcLnxâJi ^^' ^-

Section^

HUR-DLE

OS.





25

CHAPTER VII.-CLEAKING THE FOREGROUND.

For estimate of time and labour required, see table, f.120.

51. In most cases a certain amount of clearing will have to GenerMl

be done in front of a defensive position. The object should pi-iuciples.

be to secure for the defenders the full use of their weapons

within effective range, while at the same time leaving intact

or improving all existing obstacles which would impede the

free employment of the weapons of the enemy and obstructor break up his attack. When an active defence is contem-

plated (which would be the general rule) the obstacles left should

be such as not to interfere with counter-attack. In clearing Screens,

the foreground, the value of leaving screens to hide the

defenders' movements must be considered [see Chap. VIII,

Sec. 63).

It is difficult to make exact estimates of time required

to clear ground, as difficulties cannot be foreseen. The table

on p. 120 can only be taken as a rough guide for estimatingworking parties.

It will be advisable to start the clearing from the position

and work forward as time permits.

Hollows and unseen ground, which would give an enemy's

troops shelter at points dangerously near the position, may

be filled up with abatis, or debris of walls, &c.

Large scattered trees give less cover when standing than if

cut down, and may sometimes be useful as range marks.

Thick brushwood,especially in the case of

sometropical

growths, forms a very effective obstacle, which should only

be cleared away in accordance with the principles above laid

down. Thus, in place of making a general clearance, portions

may frequently be left with advantage, both to deny special

points to an enemy and to break up his attack, or to compel

the adoption of particular lines of advance (the portions cut

down may often be formed into an obstacle among the parts

left standing).

52. Hedges which interfere with the defenders' fire or screen Hedges,

the attack, must be removed.



2G CHAPTER VIII.—IMPROVEMENT OF EXISTING COVER, ETC.

The clearance of those perpendicular to the front is of less

importance than that of those parallel to the front.

Walls and 53. Walls can be knocked down by a part of men iisina abuildings, trunk cf a tree or a railway iron as a battering ram. Low

buildings may be similarly treated. If high, they must be

blown down and the ruins levelled, as far as possible, so as

CHAPTERVIII.—IMPROVEMENT OF EXISTINGCOVER, STOCKADES, &c.

For time and labour required^ see table, p. 120.

Walls. 54. Brick walls 9 inches thick, if badly built, are liable to be

penetrated through the joints by small-bore bullets, and can

he cut through by short range volleys directed on the same

spot. Practically, however, any fairly well built wall will

give good cover against musketry. Walls alone cannot be

occupied, as a rule, under effective artillery fire, but may,

nevertheless, be utilised for defence, after artillery fire has

ceased.

A wall between 4 feet and 4 feet 6 inches high can be used

as it stands. If a wall is less than I feet high, a small trench

can be sunk on the inside to gain additional cover.

Between 5 feet and 6 feet in height a wall can be notched.

(PI. 11, Fig. 4.)

Above 6 feet in height, a step must be raised inside, to

enable men to either fire over the wall, or through notches, or

else the wall must be loopholed (Fig. 5).

Loop- 55. Loopholes should not be closer together than 3 feet from

holes. centre to centre, and can be made by means of crowbars or

picks. It is desirable to make the opening on the outside as

small as possible, to lessen the chance of the entry of the bullets.

In a moderately thick brick wall the loophole may be commenced

by knocking out a " header " from the outside of the wall,

the interior dimensions of the loophole being afterwards

varied with the direction in which fire is to be delivered,

In actual warfare a rough hole only can generally be formed,



PLat& Jl

HED6E.S

Fi^. 1.

yt^^g^: NcUaraL DztcTvire rear

Fzg. Z.

t^ MtturctlliiUhTTV frortt.

WallsFig. 3

ston^ coping &.raiJbi7ig

t2vscatterecb

Fig. 4 ElevatLOTL ofFig. 8

Two Tiers ofFire

7s ^tcLoing ofPlcaiks

anJilBarrels

SancUbag loaphdU

or caiy other sort

of loophole

05Weller A Graham. L^ Lj.cho Lonuon.





CHAPTER VIII.—IMPROVEMENT OF EXISTING COVER, ETC. 27

which should, nevertheless, conform to the conditions above

laid down as far as possible.

Figs. 6 and 7 suggest methods for preparing walls for a double

tier of fire, which might be used for flanking purposes.

56. In preparing hedges for defence, weak places should be Hedges,

made up with boughs, stakes, wire, &c., and if a ditch is on

the defenders' side, little else requires to be done. If not on

the defenders' side, something in the nature of a shelter trench

may be dug, and the earth thrown up breast high against it

when such command is necessary, and if the hedge is strong

enough to support it.

In no case should excavated earth be thrown in front of the

hedge, so as to indicate its occupation.

The time required to excavate such trenches is longer than

for ordinary trenches on account of the presence of roots,

and the work required to strengthen the hedge.

In preparing a hedge for defence, if the top of the bank on

which it stands is not thick enough to keep out bullets, it

must be made so.

Hedges sometimes form very good screens for field guns.

It would generally be advisable for the guns to be in action

about 150 to 300 yards behind the hedge.57. Embankments are not as a rule good positions for a Embauk-

firing line, because they offer such a good mark to the enemy's ments.

artillery, but nevertheless embankments in front of a position

and parallel to it, will generally have to be held.

Embankments can be defended by occupying the nearer

edge, as in Fig. 1, PI. 12, or the further edge, as in Fig. 2.

The front edge gives the best command of the ground in

front, but cover can be obtained with less labour at the rear

edge.58. Either side of a cutting can be defended, according to Cuttings,

circumstances (Fig. 3). The rear side gives the best obstacle;

the front side is best for a subsequent advance, and secures good

shelter for supports.

A road cut on the side of a hill would generally be visible

to the artillery of the attack for a long distance, and therefore

should not be held unless it offers special facihties for defence.

Fig. 4 shows a method of defending a road, the fence or



28 CHAPTER VIII.—IMPROVEMENT OF EXISTING COVER, ETC

hedge on one side being converted into an obstacle^ and that

on the other used as cover.

Woods.

Woods, 59. Woods vary so much in character that it is impossible

to give general instructions for their defence suitable to all

cases. Those which reach down towards the enemy are very

dangerous and require special consideration.

The two most important attributes of woods, which are

common to nearly all, are the obstacle which they make to

the passage of troops, whether in defence or attack, and the

concealment they offer. As to the obstacle it is the defenders'

business to arrange that it shall cause the least inconvenience

to his own, and the greatest inconvenience to the enemy's

troops. The concealment afforded should be so utihsed as to

be almost entirely in favour of the defence.

The front edge of a wood very often has a boundary capable

of being easily made into a good shelter, while the materials

for abatis are at hand: In order to economise troops, especially

if the edge of the wood is indented, portions may be defended

while the remainder is entangled ; the portions to be defended

being those whence the most fire can be developed. The edge

of a wood, however, often offers a good mark for the enemy's

artillery ; for this reason it is sometimes desirable to place

the firing Hne some distance in advance.

Entrenchments and breastworks in the interior of a wood

involve great labour and should seldom be used. Where the

ground is favourable, clearances in front of interior positions

may be made, and the wood cut down made into abatis.

Log Log breastworks, especially of hard wood, will, of course,

breast- give a good deal of protection against bullets, even if it is not

complete.

If the defence of the rear of the wood is more convenient

than that of the front, the best arrangement will be to entangle

the rear edge and take up a position commanding it and some

distance behind it. The rear edge may be cut so as to leave

well defined saUents. This will induce the attackers to crowd

into these salients and so make a good target.

works.



M^teJZ

Cuttings & Embankments.

Embankments

/ly ;

/t^ 3

5 t.

Railway CuTT'MG.Jkj

;-SS?^-

Road on Hillside

y/el!er& Graham L'"= Litho London





I



PlxxjbeJS

Defence of a House

Doors.

JE^cczt^ door'Str'utte/d/

Mg.Z.

\'\yctk^ atones

^^f^ff?^^^^^WW?W^^'..

Fi^.S.

^ OjCJ' covers

Ti^.^.

IKeJIer & Graijam. L^ ituho. LondotK.

Opposite paêZ^





PUUe Uh

Defence of a HouseDoors

JFuj.^. l^:Z

JPntfrnxxL J^l^âtion

Windows.

Tlsf,3, JFzff.4^.

of2»^cJcsrL starve^ hetivejgrf.

vVer.er&G'-aham.U? ^Jtho ucndon



CHAPTER VIII.- -IMPROVEMENT OF EXISTING COVER, ETC. 29

Communications through the wood should be improved,

if the front is to be held ; if the position is in the rear of the wood

and the latter is merely to serve as an obstacle, they should

be blocked.

In making clearances, large trees should not be felled.

Much can be clone by judicious thinning.

With limited time, it ivill generally he best to occupy it in

improving the communications rather than in multiplying

obstacles.

Defence of Buildings.

60. Buildings can seldom be held under artillery fire. When Buildings,

time and labour are available they may, however, be prepared

for defence. When screened from artillery fire they are of

great value.

The principles for defence of buildings are the same as those

laid down in Chap. I, Sec. 1, but the following special points

must be dealt with :

Barricading of doors and ^vindows {see Pis. 13 and 14).

(One door should be available for use and must be

specially dealt with.) Arrangements for ventilation

(usually by upper windows) ; for storing ammunition,

provisions and water ; for a hospital and for latrines;

and precautions must be taken against fire.

Any neighbouring buildings which are not to be occupied,

should be made useless to the enemy.

If the building is large and strongly built, and it is intended

to make a determined defence, arrange for interior

defence by loophohng partition walls and upperfloors, and providing movable barricades to cover

the retreat from one part of the building to the other.

Stockades.

61. Stockades are improvised defensible walls, which, in Stockades.

addition to affording cover to their defenders, form a fair

obstacle to assault. They are only suitable for defences

of a purely passive character, where not exposed to artillery

fire.



30 CHAPTER VIII.—IMPROVEMENT OF EXISTING COVER, ETC.

The commonest forms of stockade consist of earth, gravel

or broken stones, &c., between two upright revetments

Thenecessary thickness w^ll

be obtained from the table inChap. T, Sec. 4 {see PI. 15, Fig. 1).

Eails or iron plates, if available, are useful materials. Types

of stockades of rails and sleepers are shown on PL 15, Figs. 2

and 3.

62. It must be remembered that the loopholes through which

the defenders deliver their fire should be so arranged that the

enemy, if he succeed in closing with the obstacle, will not be

able to use the loopholes in his turn.

Loopholes may be formed of sandbags or by inserting a

plank box in the earth, gravel, &:c., taking care to give some

splay to the rear to admit of lateral range. They should be

from 3 to 5 feet apart.

Loopholes may with advantage be bhnded when not in use

by an old sandbag or piece of sacking in situations where the

nature of the back ground would indicate their position clearly

to the enemy.

If required two tiers of fire can be obtained in a rail stockade

by arranging a staging of sleepers for the upper rank to stand

on, lea^nng sufficient head room underneath the staging for

the lower rank standing on the ground level. In this case

there should be a ditch in front.

Screens. 63. In these da^^s of smokeless powder the value of screens,

both for attack and defence, cannot be over-estimated. Much

can be done in a close country by judicious thinning or leaving

of woods, trees and hedgerows. Where no natural screens

exist they can be made. Smoke sometimes forms valuable

cover for working parties, especially against search hghts.

Sacks filled rather tightly with straw, left open at each end

and slit to allow the escape of the smoke, form simple and

portable smoke producers. They should be lit in the centre

of the straWj so as to burn outwards.



Piafr 15.

Stockades

topu^Ceis dH^€?t^ into qpyjxt/idL/

S'toS'ctpariy

WelU 'KGri^-aip L" urt>o Lordon





enAFTER IX.—EARTHWORKS. 31

CHAPTER IX.—EARTHWORKS.64. Earthworks may be classed generally under two heads, Earth-

viz. : Trenches and Redoubts. works.

The defences of an extended position will usually be trenches. Trenches.

They may be disposed in irregular lines arranged mainly for

frontal fire, as may be best suited to the ground, or in groups

with intervals. The ground sometimes permits of these

groups being arranged so as to provide flanking fire for the

intervals and front of other groups. In laying out such

trenches the danger of enfilade fire must be considered.

Redoubts will be used principally for isolated positions, Redoubts,

such as posts on lines of communication, or a chain of advanced

posts watching a long line of front. When placed as supports

to the front hne of an extended position they must be care-

fully withdrawn or concealed from view.

With all intrenchments invisibility is of the utmost impor- Inrisi-

tance, and is almost of as much value as the cover itself. bility.

65. Every effort should be made to utihse and improve Existing

existing cover in order to save labour and time. On the ô^^^'-

defensive there will generally be time to make a trench before

the attack commences. In attacking across open ground,

under fire, men will not, as a rule, be able to stand up and dig. Attack.

When brought to a halt, they will have to make such cover as

they can while lying down, but no opportunity should be lost

of entrenching ground that has been gained.

Siting of Trenches—{See also " Combined Training," 1905,

Section 126).

66. The following points must be considered : Siting of

A good field of fire ; this is most important and should trenches.

not be sacrificed to any other consideration.

As much concealment as possible, particularly from the

enemy's artillery.

Ground in rear suitable for reserves.

When the position includes commanding ground the

firing hne need not necessarily be on it; it should be



32 CHAPTER IX.—EARTHWORKS.

Arrangfe-

ment of

trenches.

in the best position for fire effect. It will often be a good

plan to place the firing line at or near the foot of a slope,

so as to obtain a grazing fire, with the artillery on the high

ground above.

The advantage of high ground for a defeusive position is

often over-estimated. It need oidy be high enough to conceal

and shelter the defenders' reserves and their movements, and

to expose the movements of the enemy.

67. The arrangement of trenches should be simple. There

should be one main line of defence. Several tiers of trenches

may sometimes be useful, to increase the volume of defenders'

fire, and also to deceive the attack as to the actual position of

the defence ; but there should be no idea of using these trenches

as successive lines of defence. The defenders should understand

clearly which is the main line of defence, and what it is that

they must hold on to when the assault is pushed home.

The main line should not as a rule be continuous. If

echelonned in suitable lengths, say for companies, or even

smaller units, it will be more difficult for the enemy's

artillery to get the range.

In tracing a trench attention should be paid to probableenfilade fire.

Every artifice should be used to mislead the enemy as to

the positions of the trenches, e.g., conspicuous dummy trenches

to draw his fire.

Invisibility.

Tnvisi- 68. Every effort should be made to conceal the trench.

biiity.

Concealment may be gained by (a) careful siting, i.e.,

position, (h) Assimilation to surrounding ground. When

possible a position should be studied both before and after the

construction of trenches from the front, and especially from

the enemy's artillery positions. Well-marked features of

the ground, such as isolated hedge-rows, Hues of road, sharp

changes of gradient, or anything which casts a shadow are,

at long ranges, more visible than the trenches themselves.

The neighbourhood of such objects forms a target, especially

for artillery fiie, and should when possible be avoided.





PlrrJe JO

Fire Trench es

Surplus ea7*th. m/iyhe hecuped- or sprecLeL

in. re^xr of trerhcJv

*806-S aswe'-e'SiGraâT' L'' iJtio Lonoon

Opposite pajqie.33.



CHAPTER IX.—EARTHWORKS. 33

The front of the parapet maybe covered with sods or branches,

or whatever will make them look like the surrounding ground.

Sharp hues must be avoided and attention must be paid to

back ground.

If the parapet is on the skyline, spare earth may be piled

up behind the trench to make a back ground for the defenders'

heads. As a rule, however, a sky line is to be avoided.

The parapet should be kept as low as possible consistent

with fire effect ; in some cases no parapet is required.

Trenches.

69 . Trenches are distinguished as "fire trenches" and "cover Trenches,

trenches," according as they are for the firing line or merely

to cover troops not actually engaged.

Fire Trenches.

70. The design of the trench will depend on the time and Fire

labour available, on the soil and on the siting, but the following trendies,

points are important :

(1) The parapet should be bullet proof at the top; 2 feet

6 inches to 3 feet will iLsually suffice. But see Sec. i.

(2) The trench should be as invisible as possible.

(3) The interior slope should be as steep as possible.

(4) The bottom of the trench (unless there is a step)

should be wide enough to allow men to sit in it.

(5) The interior should be protected, as far as possible,

against oblique and enfilade fire, and sometimes from

reverse fire,

(G) Drainage should be attended to.

71. Types of fire trench are given in Pis. 16 and 17, but see

Sec. .3.

Fig. 1 gives good cover against frontal artillery fire,

and allows room for the supernumerary rank to pass behind

the firing line.

To excavate the normal length of 2 paces of this trench

will take an untrained man about H hours, in moderately

easy ground.

(528'J) c





R^Ltt J 7







PZccLe JS.

Head Cover .

SojixL'bcuf Loophjole with. Loophole Plcutes

on Leiêl^ groujvcL.

Ftg. 1 Fig. Z

Section

Fi€f. 3

Sandbag Loophol e

Sod

Plan of j*ir Courses Plan of^&tt Courses

Stbdks to cccrry

tap soTLdba^s

S ECTION

ler&Graham.L" Urho, London



CHAPTER IX.~ EARTHWORKS^ 35

earth. The size of the openings must be governed by the

ground to be covered by fire,* and can best be regulated bytesting with a rifle with the bolt removed to ensure that

neither line of sight nor line of fire are obstructed.

Sandbag loopholes, as shown in PI. 18, Figs. 3 and 4, can be Sandbag

made in a continuous line as close as 3 feet 3 inches from loophole,

centre to centre.

Sandbags sag a good deal unless well supported.

Loopholes made with earth or sandbags may have the larger

opening either inside or outside. If the larger opening be

inside, the loophole is verymuch

less conspicuous, which is

often a point of great importance.

If the larger opening be outside, a defender can fire with much

greater ease, since he can cover the whole arc without moving

his position.

The choice must depend upon the requirements of the place.

A compromise between the two above methods is shown in,

PI. 19, Fig. 1.

A very good form of loophole which has the advantage of Con-

giving a wide field of view, is a slit all round the work, tinnous

continuous, except for the supports of the material above {see^^^ ^^ ^'

PL 25).

Loopholes made with hard material, such as stone, must have

the larger opening inside to prevent ricochet.

Steel loophole plates, see Figs. 1 and 2, PI. 18, are articles of Steel

store. They make the best head cover, but cannot, as a rule, loophole

be provided for hasty defence work.plates.

Loopholes should never show against the skyline, but

should be blinded, say, by canvas hung behind them. The

front of the loophole may be masked with branches, long

grass, fee.

Overhead Cover.

73. Overhead cover gives the best protection against

shrapnel from guns and howitzers. It is especially useful

* The minhiium depth of openings for a parapet 2 feet 6 inches tliick

on level ground, using the new service rirte at 2,000 yards range, is, for

the inside, six inches ; for the outside, four inches.

(5289) c 2



3G CHAPTER IX,—EARTHWORKS.

against oblique fire ; 9 to 12 inches of earth, or say 3 inches

of shingle, supported by brushwood or other suitable material,

will suffice. (PI. 20.)

Two sheets of corrugated iron sloping to the rear at about |,

afford good protection against shrapnel {see PL 19.) The

corrugations must be parallel to the line of fire.

Overhead cover of above natures will not keep out a common

shell, but the effect of a burst in the trench can be locahsed

{see below).

A row of heavy steel rails arranged in the same way as the

corrugated iron, has been found to be practically proof against

G-inch howitzer shells filled with high explosive.

Overhead cover against weather may be made with

branches, corrugated iron, canvas, or any other covering

available.

See also Sec. 88.

Traverses.

Traverses. 74. Open trenches and parapets which may be exposed to

enfilade fire and to the oblique fire of artillery, should be

traversed and recessed. Traverses are simple means of

gaining protection against enfilading shell, and also of localis-

ing the effect of a shell bursting in the trench. They are also

effective against rifle bullets, on account of their flat trajectory.

An irregular fine of trench will answer the same purpose, when

it suits the ground.

Against shrapnel bullets coming obliquely, or in enfilade,

traverses will not suffice, on account of the steep angle of

descent of the bullets. Eecesses made in the parapet, larê

enough to hold one or two men, give the best protection against

these. See PL 21. Such recesses are best made after the

trench is excavated.

75. Traverses to localise bursts may consist of two walls of

brushwood, with about 1 foot of earth between.

Protected Look-out.

Look-out. 76. In all trenches some sort of protected look-out is useful.

It should not be distinguishable from the front.A well-made loophole may suffice for this purpose.



Flate. J9.

Fi^.1.

Sod Loophole

J^.2

ês\

SocLs

Sods

Overhead Cover-K / 6

Welter & Graham. L^f Litho London.





PUlIa 20



\,



TTmni

3. I





PLote 22

Gun Epaulment.

Fr^l

\ 7'.^" .^ SecwoTL on, A .a

» V*~^-/2«ORy-$" for cortt&vt^ o^ <nieJrn.7rSUhô7z,

J-,^. 4.

^ +3'

Fig. 5.

SectUnv across Wixôn Grver.

\^ -

j^ LenxjftTh aucc^rdiTui toTva/nber*

WetlerAGraham. L'^ Lirtio,Lx)ndon.





Piate 23

CO

Gu N ;Pi t .

(On rear crest ifv/t/r wkson coi>êr/n near)

F^—irt GUN PIT

'%1li]!iLli%

^^

-30

88

'^ k:

/O'

^

rear crest of hill

COVER FOR ^WAGONS. ^

<..

Section on AB -/-/•6

Section

•r..

we;!ers.r-a-3r





chaftrr ix.— earthworks.^

37

Drainage of Trenches.

77. This is an important point, and should be attended r)rainage.

tofrom the outset.

Agutter should be formed in the trench,

usually at the back, and the bottom of the trench sloped to

it. Any water collecting in it should, where possible, be led off

to lower ground, otherwise into soak pits, which may be about

2 feet or 3 feet in diameter and 3 feet deep.

Communication Trenches.

78. If time admits covered communications should be Communi-

arranfTed behind the firine line. These, while concealing thecation

movements of the defenders, will also permit of the firing line

being withdrawn altogether while the artillery bombardment is

going on. A trench similar to PI. 16, Fig. 4, will usually

suffice.

It may be necessary to make long lines of such approaches,

but every possible use should be made of the ground to mini-

mise labour on them.

They may require parapets on both sides, and where much

exposed may be given overhead cover.

Cover Trenches.

79. Cover trenches {see PI. 24, Fig. 1) are useful to protect the Cover

firing line during a bombardment, and for troops not actually trenches,

engaged.

The section of these trenches may be as in that figure, or,

if more time and material be available, as in Pis. 28 and 29.

When time is limited and materials are not at hand, a section

similar to PI. 16, Fig. 1, might be employed, but with slightly

higher parapet and no elbow rest.

Cover for Artillery.

80. Cover for field guns will take the form of epaulments, or Cover

pits, as shown in Pis. 22 and 23. An ammunition recess must for

be provided close to the gun, and cover for one or more ammu- ^^'"^^^7-

nition wagons near the emplacement is also desirable. There

should be covered communication between the gun emplace-

ment and the wagons. Parapets to be bullet and sphnter







Plate Z^.

C over Trenches

Fig r

REDOUBT(Low Command)111

.

GerveâL JPZccn^

JE^,Z^

JUL -K---. WIL

"IVTi^N. lOrrven^ X 10.me^ -<''XA'\

JPlany of^Shelter'S.

430S.B OS.Welleri Graham. L'^ Irrtio.LonJorv,





FJjubt 25.

</eli»rfcGraha(» V* Lirtio.London



CHAPTER IX.—EARTHWORKS. 39

84. The site should be such that the surrounding foreground Site,

may be well swept by the fire from the parapet, and the work

should be so disposed as to give the strongest possible fire on

the enemy's best lines of attack. There must be no dead angles.

A redoubt may be of any shape that suits the ground and

provides good firing fines. There is no necessity for symmetry

in the design, although it has advantages. On a level site

a rectangle with blunted angles would be suitable.

All faces should be long enough to give an effective fire.

Those making a considerable angle with neighbouring faces,

as in a rectangle, should not be less than 20 yards long, and

the short faces which blunt the angles should be at least

10 yards.

It is often convenient to use curved faces. These, as a rule,

should be struck with a radius of not less than 20 yards.

A complete circle should be avoided, except for very small posts,

as its fire is weak in every direction.

85. The garrison should always consist of one or more Garrison,

units of command. The proportion of defenders, including

supports and local reserves, to size of work should be from

1 to IJ men per yard of parapet, but the proportion of

parapet to men may have to be much larger.

86. In a redoubt in front line exposed to artillery fire Low

invisibihty is the first consideration. This will entail in most command

cases a low command, about the same as that of the neighbour-I'^doubt.

ing fire trenches. This should be combined, w^hen time per-

mits, with a deep trench in rear, both to increase the cover

and to afford cover to troops not actually engaged. A redoubt

of this type is shown on Pis. 24 and 25.

87. For a work placed as a supporting point behind the High

front line, the question of invisibility is not generally so urgent, commandIn this case a high command has four advantages :

(1) It has a better command of its field of fire than a low

redoubt.

(2) It has a better moral effect on its defenders.

(3) It conceals the whole of the interior of the redoubt

from view.

(4) It can be easily combined with a good obstacle.





Ql<

I

ml

I Si

hCQ

DOQUJ! ofti

' UJ:

z °

O' -,

Ol uii

i U):

X' ^'

O >—

I <

> oUJ o

°-5O 111

u

H g ,6

Ul <0 (/)

O UJ (/>

«*;^

z o 0^

- _i o^ ^ ô o o

> 08 >-

l> =

? UJ ^

° J iy H >

Z10

<

UJ <

si

2 oO I-> 10

WtllerfcGrdhdni. L'^ Lirho.London

Opposite pajCfB' 40





WeilertGraham L'.' Litho,London

To folZow plaJ^. Z6.





/^lal^ 2S

WellerlGrshamf* Urho.Looden





Vlat^ 29

HASTY R EDOU BTBLINDAGE IN REAR OF FIRE TRENCH

SectCoTh t/iro ' îCrtjcLcyfe^ .

Weiler* Graham. L"" LiLho London





CHAPTER X.—OBSTACLES. 41

92. Obstacles should always be provided in connection Obstacles,

with redoubts. They must not mark the jôsition of the

redoubts.

The nearer the obstacle is to the parapet the less labour

and material will be required, and the more efiective will be

the defence, especially at night.

CHAPTER X.—OBSTACLES.

For time, labour, tools aiid material required, see table, p. 120.

93. Obstacles judiciously placed add very much to the strength General

of a defensive position, and are especially useful as a protection eonditious

against night attacks. The following conditions should be

observed :

(a) They should be under the close rifle fire of the defender.

For small posts or redoubts they shouldbe

quite close,

so that they may be effectively defended at night.

They should afford the enemy no cover, and, if

possible, be sheltered from his artillery fire.

(b) They should be difficult to remove or surmount, and

will be most effective if special appliances, not usually

carried by troops, are required for their removal.

(c) They should, if possible, be so placed that their exact

position may be unknown to the attacking force.

(d) Except where the purely defensive is inevitable, they

should be arranged so as not to impede counter

attacks.

(e) As obstacles on a large scale may interfere with an Caution.

advance, they should not be constructed without

authority.

For the protection of small posts at night some sort of

automatic alarm is desirable, such as tins hung on a wire,

rifles fired by trip wire, &c., see p. 47.



42 CHAPTER X.—OBSTACLES.

abatis. 94. Abatis formed of limbs of trees firmly picketed down and

interlaced, with the branches turned towards the enemy

and pointed, form a very efficient obstacle (PI. 30).

Figs. 1 and 2 show method of covering abatis from artillery

fire.

Fig. 3.—The method of forming an abatis from small

branches. Several rows are used, the excavated earth being

replaced after the branches are secured. To make abatis

carefully, at least a relief of six hours and a strong working party

are required, so that very little of it can be undertaken in

hastily-fortified positions. A very effective abatis may, how-

ever, be made much more rapidly when the trees can be

utilised where they are felled, no excavation being made for

them and the branches being only roughly trimmed.

Strands of wire interlaced between the branches are a useful

adjunct to abatis.

Tree 95. Tree entanglements (Fig. 4, PI. 30) are formed by cutting

entangle-trees, brushwood, &c., nearly through at a height of about

3 feet, and interlacing or securing the branches by pickets

to the ground. They make a formidable obstacle at the edges

of woods and orchards, and for blocking roads, and can often

be formed w^hilst clearing the foreground.

Wire 96. A low wire entanglement is formed by stout stakes

entangle- (Jnyen into the ground about 6 feet apart, in rows arranged

Low^' chequerwise, their heads being connected by strong wîres

twisted round them and crossing diagonally about 1 foot or

18 inches above the ground (Fig. 3, PL 31).

The outside pickets should have ware stays, as shown in

Fig. 3.

It is not a good obstacle unless constructed amongst brush-wood, small bushes, or long grass, which conceal it, when it

may be of great use against mounted troops. It is especially

effective in the bed of a river.

High. 97. High wire entanglements form effective obstacles, es-

pecially if barbed wire be used. PI. 31, Figs. 1 and 4, give

two different types. Fig. 4 shows a method of improving a

wire fence, but is not so efficient an obstacle as that shown in

ments.



I^lcutG 30.

ObstaclesAbatis.

j^ 1

Palisades

Fi^.5

4< N A

1

K

I

l'' '

'i iil 'I]I

" 111 '; "I |I|iil '-11 'I' 'I

1I

FlxuL of PcLbuscule

Welter & Graham. L^ LithaLowJon.







Pictte^Sl.

F^,1.

Obstacles .

High wire Entanqlement

DixfjônxxX -yytres .<ihou2jdb he' ccivrvecfeel^ by TwruumtaZ'-wJT-'&s omxtted^ yyt, J^jgr J . ibr- seeks of deaTm^s^.

the^ 'hjori;z/7T€taX m/lt^s are cdjba^KfjJf.

Fi^.3 Low WIRE Entanglement.Stof

Fz^ i .

Barbed wires

WcJIcr 4 Graham. L**^ UthoLondon.



CHAPTER X.—OBSTACLES. 43

Fig. 1. The pickets should be about 4 or 5 feet high, driven

firmly into the ground and sta3êd as in the low wire

entanglement.

Where two wires cross they should be fastened together withfine wire or string. Where materials are available the obstacle

should be two or three rows deep.

98. Palisades are occasionally used for the defence of ditches, Palisades,

and for closing the rear or gorges of partially enclosed works.

They would principally be employed in savage warfare. They

are made of timbers about 10 feet long, arranged so as to form

a stout open paling, and pointed or spiked at the top. The

timbers may be round, spUt, or sawn to a rectangular or tri-

angular section ;

they should be 6 inches to 8 inches wide,and are placed upright about 4 inches apart, and spiked

to two ribands about 1 foot from either end, the butt ends

being sunk 3 feet or 4 feet into the ground. The top riband

should be on the defenders' side of the palisade. They are

most conveniently made and placed in lengths of 10 feet or

12 feet, the ribands being arranged so as to overlap.

(PI. 30, Fig. 5.)

99. Fraises are palisades placed horizontally, or nearly so. Fraises.

They should point downwards if placed on the defenders'side of the ditch and upwards if on the enemy's side. Both

ribands are buried, the one nearest the points being placed

underneath, the other on top. The points should, if possible,

be at least 7 feet above the bottom of a ditch.

100. Barricades, used to close streets, roads and bridges, Barri-

can be made of any materials at hand. They should not, as a cades,

rule, completely close the road to traffic, but be made in two

overlapping portions, or be placed where a house standing

back from the general line of building allowsa passage round

the barricade.

The defenders should be able to fire over them, and, if

placed in a street, they should be flanked both in front and

rear by the fire from adjacent houses.

101. Foagasses and land mines {see "Instruction in Military Foujjas'es

Engineering," Part I) are a useful adjunct to the defence. ^"^ ^*"*1

They should only be laid by officers who have a thorough^^^°^^'

knowledge of explosives.





CHAPTER XI.—DEFENCE OF POSTS AND VILLAGES. 45

107. Every man employed on communications is in a sense Scheme of

wasted, therefore the garrisons of such posts must be kept as i^ptV-nce,

low as possible, and every effort made by the skilful use of g^'"'^**^°^'

ground and field fortifications to economise men.

The main princij^les to bear in mind are as follows :

{a) Organisation of defence.

(b) Defenders to be close to the ground they have to defend.

(c) Storage of ammunition, water and supplies. Strong

obstacles (automatic alarms if possible).

{d) Clear field of fire, adequate cover, good communica-

tions, including telephones, telegraphs, or a well

organised system of signalUng.

Plenty of time is usually available for the organisation

of the defence, and in these days of rapid fire, given adequate

supplies of ammunition, food, water and material, small posts

can be made practically impregnable against raid attacks,

even though the invaders be accompanied by a few guns;

while larger posts can be so held that, even should the enemy

be able to penetrate under cover of darkness, the risk and

loss involved would be hardly worth the attempt.

Owing to the paucity of troops the defence will usually

be entirely passive, and except for a small reserve to meet

emergencies, every man will have his post assigned to him,

and every rifle will be in the first hne. Works and picquets

suddenly attacked at night cannot, as a rule, be reinforced from

a distance, and for this reason it is essential that the garrisons

told off for the defence of such works should live quite close to

them.

108. The defence of a post of class (a) (Sec.105)

will consist Detail,

of a ring of closed works supporting each other ; the number and

distance from the centre will depend on the ground and troops

available; the intervals will be closed by a strong obstacle,

which latter must be flanked by a fire from the works. The

works themselves, in view of a night attack, must be sur-

rounded by an efficient obstacle at a very close range, say

20 to 50 yards. The field of fire must, of course, be cleared as

much as possible. In most cases an inner hne of defences

will also be required, and possibly a " keep.'*



4G CHAPTER XI.—IJEFENCE OF POSTS, VILLAGES, ETC.

Tiiis ring of defences will not be of as elaborate a pattern

as those of the outer line, described in the paragraph following,

and will generally consist of fortified houses, garden enclosures,

small blockhouses, &c., placed in the immediate outskirts

of the village or depot, and arranged so as to sweep all approaches

and internal communications.

The posts of class (6) will consist of only one or two of the

above works, and their garrisons may vary from say 6 to 50

men.

Type of 109. The types of works will necessarily depend on the nature

work.

Qf ^]^Q probable attack. If the enemy is provided with artillery

deep trenches and splinter proof cover must be provided

(unless the ground affords adequate cover close at hand)

against rifles only, walls or blockhouses may suffice. Against

badly armed savages stockaded enclosures are good enough.

Invisibility is not essential, but every effort must be taken,

with due regard to effective rifle fire, to protect the defenders.

To this end head cover is necessary, and overhead cover often

desirable, while, since the attack is hkely to come from every

direction, enfilade and reversefire

must beconsidered.

Eachof these closed works must be self-contained, the storage of

reserve ammunition and water is imperative.

Design HQ. The construction of the works will mainly depend onconstrue-

^^le materials locally available. South Africa produced corru-

uorks. gated iron and shingle blockhouses surrounded by barbed

wire ; on the north-west frontier of India stone sangars are

the rule ; in the Lushai Expedition of 1889 bamboo stockades

were made ; in the Soudan breastworks of sand and thorn

zerebas. Where railway stations have to be protected,

blockhouses, stockades and splinter proofs made of rails and

loopholed buildings will predominate, while for a bridge the

piers and girders can often, with a little ingenuity, be made

into good cover for a small post.

In savage warfare the best hints as to designs may generally

be got from the enemy, who, in the course of intertribal warfare,

will most likely have evolved the types of defence best suited

for local materials, and to resist the same form of attack and

weapons which he will employ against us. Such types, when

improved by the light of our own knowledge, modified to



£iiZ££z



Defence of a Post on a line of Communication s .

{Springfontein —South African iVar/899-OZ .)

1 nil

FORU® i^ÛCvmphmaitfafftflea



TUjcLc 33

Defensi ble PostUcHA Jawa 1897.









I'Ujt, :i5

Defensible Post .

LusHAi 1889 .

(For section across Stockade^ see P/ate ^Z.)

7'o foUjn^' pljoJj^J^}





pixxju. se

welier 6. Graham. Lf^ brt>o,Loix»«fl

To follow pCaJ^35.





PUitsSl,

in

O

Xoo_»

CCS

Q^l

51

a:'I

°=!

o





MxxtBJS

SECTION A.B

Weller&Graham L"^ L





JPlxjte 39

WelleriGraham ' *.* Li»t\o.London

To foiLo^y pUf^ 38.





Flrrfe ^0

VVcller* Graham. Ltd Litho.London





Tlate 4i.

7b foOoM pl^xte. 4€.





*?



Flrite^ 42

Fixed Rifle Batteries.

/%./ z. s

Caracas 16 -vvvd^t-

Z'A' 7 slot'3 lrj7i^ T^fi/Jv strvnâ

3 ^ 1 /z

i....

4•6""

^curthi\

r-*-».,»,^

Fvg.2 .

Elevation .

^y[J.j>l'?ie z -^"^ z:_

,yL ....>.

,f^X B,

eloTTfip

! S'V/z

430& :eWellerjr Graham, L?^ Litho. London,









48 CHAPTER XL—DEFENCE OF POSTS, VILLAGES, ETC.

a man raising his rifle barrel too high. Posts painted white

on the defenders' side make a good aiming mark, if the night is

not too dark.Steel loop- 115. Loopholes made of sandbags, sods, &c., unless very-

holes, carefully made, do not afford a good field of view and fire

combined with adequate protection. To meet this objection

a steel loophole plate has been introduced into the service. It

would be specially useful for det?vched posts. {See PI. 18,

Fips. 1 and 2.)

Entrances. H g. The entrances to closed works must be carefully attended

to. They may be closed by a gate, barbed wire or other

obstacle. When wire is used, a good plan is to construct anintricate winding approach, making access by night difficult.

In all cases entrances must be covered by the fire of the defence.

Entrances to admit artillery require a width of 7 feet.

Defence of Villages.

Tillages. 117, Villages will very often occur in or near a defensive

position, and although they are unsatisfactory for defence they

must generally be occupied, rather than be left to the enemy.

They conceal the disposition and strength of their garrisons,

and afford a shelter from the weather, but they take up a large

number of men who are necessarily scattered.

A village should be divided up into well defined sections,

each held by a tactical unit. Each section might have two

lines of defence. There will be a general reserve for the

whole under the commander of the village, to reinforce a hard

pressed section, make local counter attacks, and furnish the

garrison of the central keep of the village, if any.

1 18. The arrangements of the defence might therefore be as

follows :

(1) Clearing field of fire.

(2) Making communications.

(3) Providing or improving cover for first line along

hedges, garden walls, &c., loopholing walls of houses

as a second line.

(4) Placing obstacles. This would be partly done at

the same time as (1).

i(5) Preparing keeps.









50 CHAPTER XI.—DEFENCE OP POSTS, VILLAGES, ETC.

Organisation for Defence of Large Positions.

Defensive 121. In order to ensure a good system of command andpositions. orp;anisation, defensive positions should be divided into well-

defined sections, each under a separate commander, to whomshould be allotted a distinct force, e.g., a division, brigade,

etc. {see " Combined Training ").

Each section commander will be responsible for the

occupation and preparation for defence of his section in

accordance with the orders received. He will either indent

on the service or department concerned, or may make

arrangements by hire, contract, or requisition with the local

civil authorities, according to the circumstances of the case,

for such extra labour, tools or materials, as may be required.

For Tables, giving roughly time required for various works

and form for working parties, which will be found useful in

connection with the above, see pp. 120 and 136a.



51

CHAPTER XIL—TEMPORARY ROADS.

1 22. Temporary communications by road are usually Tem-required :—

" vovnvy

(a) In comiection with a defensive position to enable'-°°^™^'^^"

^ ' , -,., -IP • cations,

troops to be readily moved irom one portion to

another.

{b) For the movement across country of detached

columns.

In both cases provision will generally have to be made for

wheeled vehicles, while simple means to enable the infantry to

pass dryshod over water should not be neglected. The pro-vision or improvement of such communications can, as a rule,

be carried out bv unskilled labour. For more permanent work

see Chap. XXII, Part II.

Communications inside a position will consist in repairing

existing roads. filUng up soft places, cutting ramps in steep

ground, cutting gaps through fences and clearing roads or

paths through woods.

The points to be kept in mind are : That troops should be

able to move on as broad a front as possible, and that troops

and messengers should be guided to their destination by sign-

posts, by " blazing " trees or other means.

The work in connection with detached columns will generally

consist in repairing existing tracks or fords and making boggy

or soft ground fit for wheeled transport.

Since soft ground, even though passable, is very trying to

draft animals and causes delay, a little labour, well applied, will

be amply repaid.

123. The best foundation for a temporary road over boggyTem-ground is a layer or layers of fascines placed touching one porary

another ; the top row must he across the direction of the ^'^''^^^ o^^'^'

traffic, but when time is not available or suitable material notgpf^nd

at hand, much can be done by throwing down brushwood,

heather, or even straw or grass, care being taken that this,

like the fascines, is laid across the road.

If there is much wheeled transport, a reserve of material

should be collected to replace any that gets worn through.

(5289) D 2



52 CHAPTER Xlir.—KNOTTING AND LASHINGS.

In very wet ground it may be necessary to dig a drain on

each side of the road {see PL 82, Fig. 3).

Corduroy 124. Where timber is available and heavy traffic is expected,

road. a " corduroy " road may be made. This is constructed by

felling trees, cutting them to the required lengths and laying

them across the road at right angles to its direction, ribands

being spiked to them at either end ; or the logs may be held

together by interlacing with rope or wire.

The interstices between fascines, brushwood, logs, &c., maybe fUled with small stones and earth to make a better surface.

CHAPTER XIII.—KNOTTING AND LASHINGS.

Knots and 125. The following are the most useful knots for bridging

bitches. and lashing spars, and their principal uses :

(a) To make a knot on a rope, or to prevent the end from

unfraying, or to prevent its sUpping through a block;

the thumb knot (Fig. 1, PL 45) or the fgure of 8(Fig. 2).

{h) To hend or join two ropes together. The reef knot

(Fig. 3) for dry ropes of the same size; the single

sheet hend (Fig. 4) for dr\^ ropes of different sizes;

the double sheet bend (Fig. .5) for great security or

for wet ropes of different sizes, and the hawser hend

(Fig. 6) for joining large cables.

(c) To form a loop or bight on a rope which will not slip.

The bowline (Figs. 7 and 8) for a loop at the end of arope, the bowline on a bigh^ (Fig. 9) for a loop in the

middle, with a double of the rope.

[d) To secure the ends of ropes to spars, pickets, &c., or to

other ropes.

Half hitch (Fig. 4, PL 46) for securing the loose ends

of lashiDgs, &c.

Clove hitch (Figs. 1 and 2, PL 46) (two half hitches)

generally used for the commencement and finish of

lashings.



:FZjcct^ 4-5.

KNOTS

:Fiy.5.

SeiscLrzg

J^.9.

JôWlznje^

OBW<ll«ri Graham. Lô Litho.Undon.





Plat^46.

KNOTS.

ZMaZfJIibch^

Jî^.^.

Z^cd/'JBztohês. JBervdy

JY^.S. JF^.^.

(Umzrrfjenc/eciy

f 8.99.Weller & Graham, L^ LithaUsiion.





.I^Jt^ 4/7.

KNOTS

SFr-^.CoctkjPa4y,(m/

corrurvenjeedy

StopptfT

JVy.S.Anf^

Jjsn^torL^

Shirwr/210 ou Gash/

9S, #eHer*Oraham.-L!- Litlw. Lontfoiv

To fbULowplatje 4-G





CHAPTER XIII.—KNOTTING AND LASHINGS. 53

Timher hitch (Fig. 3) for catching hold of timber, &c.,

where the weight ^vill keep the hitch taut.

Round turn and two half hitches [or rolling bend) (Fig. 5)

for belaying (or making fast) a rope so that the strain

on the rope shall not jamb the hitches.

This will be used for making fast a rope to a bollard

or anchorage. Should the running end be incon-

veniently long, a bight of it should be used to form

the half hitches.

Fishermen's bend (Fig. 6), for making fast when there

is a give-and-take motion, e.g., for bending a cable to

an anchor,(e) To fix a spar or stick across a rope.

Lever hitch (Fig. 7), for drawing pickets by a lever and

fulcrum, fixing the rounds of a rope ladder, fixing

bars to dragropes, &c. v

(/) For forming a loop on dragropes.

Man's harness hitch (Figs. 7 and 8), the loop being of a

size to pass over a man's shoulder.

{g) To fix a rope with a weight on it rapidly to a block.

Catspaw at the end (Figs. 1 and 2, PL 47) or in themiddle of a rope (Fig. 3), for hooking on a block.

Blachvall hitch (Fig. 5), a simple hitch (with a pliant

rope) which will only hold as long as the weight i^'

applied.

(h) To transfer the strain on one rope to another.

Stopper hitch (Fig. 4), for use on occasions when it is

necessary to shift the strain off a rope temporarily.

126. To sling a cask horizontally. Make a long bight with a siingmg

bowline and apply as shown in Fig. 6. casks.

To sling a cask vertically (Fig. 7). Place the cask in a bight

at the end of the rope, and with the running end make a

thumb knot round the standing part of the rope. Open out

the thumb knot and slip it down the sides of the cask. Secure

with a bowline.

127. A rack lashing, an article of store, consists of a length Rack

of 1J-inch rope, with a pointed stick at one end. Used forlathing,

fastening down ribands at the edge of the roadway of bridges.



54 CHAPTER XIII.—KNOTTING AND LASHINGS.

BclaTing.

Commenced with a thumb knot at a, Fig. 1, PI. 48, the end

t\visted in the bight. The stick is then put into the bight,

t^^^sted against the hands of the clock till all is taut, andfinalh^ jammed in from right to left between the lashing and

the outside of the riband. A rack lashing is readily impro-

vised (Figs. 1 and 2, PI. 48).

128. To belay a cable to belaying cleats. First take a round

turn \\ath the standing part of the cable on the belaying cleats,

then as many figure of 8 turns as necessary. Half hitches are

on no account to be used in belaying any rope which is likely

to have to be cast off quickly.

Square or

transom

lashing.

Dingonal

liisbing.

Lasliing

block.

Lashings.

129. To lash one spar square across another, commence by a

clove hitch on spar a below h, PI. 48, and twist ends together,

carry at least four times round the spars, as shown in figure,

keeping outside previous turns on one spar and inside on the

other ; two or more frapping or cross turns are then taken, the

corners of the lashings being well " beaten in " during the

process, and finished off with two half hitches round the mostconvenient spar (Figs. 3 and 4, PI. 48).

When the spars are the leg and transom of a trestle or frame,

the clove hitches should be on the leg below the transom,

and the lashings should be finished off on the transom outside

the leg.

130. To lash two spars together that tend to spring apart.

Begin with a timber hitch or running bowline round both

spars and draw them together, then take three or four turns

across each fork andfinish

with frappingturns

and twohalf

hitches. (Fig. 5).

Wedges with well rounded points are often useful for tighten-

ing lashings. They are generally used by builders in scaffolding,

and should be driven in at the top of the lashings.

131. To lash a block to a spar.—The back of the hook is laid

against the spar, a clove hitch is taken round the spar above

the hook, then several turns round the hook and spar, and

finished off with two half hitches round the spar below the

hook (Fig. 6).



LASHINGS

r/aia.48.

JFz^.^Jtct/*k/ JOcLshinjq

TUf.S. Tig. 4-. :Fiff.5

IWUZB

JFu/.7. So7^fciSty









I'lcctÂU

TYPES O? BRIDGES.

Tia. 7.

'-"-^

jn^.s

Sf-iff.^-.







P/^.//? oO

s,3e.6. OS.

BRIDGES

Fu/.^.

Weiler&Gradam. L!r' Lirho.London

OpposLte pouje 51.



CHAPTER XIV.—BRIDGES. 57

141. The same nature of roadway can be applied to cacli Construc-

type of bridge, and its usual form is shown in PL 50, Fig. 1.^'^^^ ^^

The planks or chesses, A, A, placed across the width of^^^^ ^*^'

roadway are supported on longitudinal baulks or road-bearers,

B, B, which in their turn rest on transverse transoms, T, T, and

the method of supporting these last depends on the type of

bridge. The chesses are kept steady by two ribands, R, R,

which are secured to the outside baulks either by rack lashings

or by lacing, or the chesses may be simply nailed down.

142. A width of 8 feet in the clear—^.e., the clear space between Width of

the ribands—suffices for infantry in fours, for military vehicles in roadway.

one direction, and for c&Yalvj in. half-sections—i.e., two abreast;

but 9 feet in the clear is a better width, especially when there is

likely to be a sway on the roadway, as frequently happens in

the case of floating and suspension bridges.

The " normal " width of bridge is 9 feet in the clear.

Six feet will take infantry in file, cavalry in single file, and

field guns passed over by hand ; IJ feet to 3 feet will take

infantry in single file.

143. Planks IJ inches to 2 inches thick are sufficient for Chesses.

ordinary traffic.

For continuous or heavy wheeled traffic additional chesses

should be laid longitudinally, to form wheel tracks.

Chesses can be economised, if they are longer than the width

of the bridge, by placing them diagonally.

Hurdles, short fascines, corrugated iron, &c., can be used

in lieu of planks, but are not good for horse traffic.

When material is available, chesses may be laid on the ground

on the banks on each side for a short distance, to allow horses

to become accustomed to the noise before actually getting

on to the bridge.

1 4 4. A handrail should be provided, especially for horse traffic. Handrail

They must be strongly built. Screens on either side are desirable and

for passing animals over a bridge, especially over running water,^^êens.

145. In most bridges the ribands should be fairly pliant, in Ribands,

order that the rack lashings may press them tightly down on

the chesses throughout. In suspension and floating bridges,

however, stiff ribands are desirable, as they tend to stiffen

the bridge.



58 CHAPTER XIV.^-BRIDGES.

Rack lashings should be applied at intervals of 4 feet or

5 feet.

Baulks. 146. The number of baulks depends upon the size of thetimber available. They should be sufficiently close together

to support the chesses.

Bays. 147. The distance bridged by one set of baulks, i.e., the

distance between any two transoms, is called a hay.

The length of bays depends chiefly upon the size of available

baulks ; 10 feet to 15 feet is a convenient length.

When the trestles are large, material and labour should

be economised by making the bay as wide as the length

and strength of the available road-bearers will allow.Strength 148. Whatever arm of the service it is constructed to carry,

of bridges. ^ bridge should be capable of supporting it when crowded

in the formation for which it is intended. Thus a bridge

intended to carry infantry in fours should be strong enough to

take infantr}^ in fours when crowded.

A bridge that will carry infantry in fours crowded at

a check wiU carry field guns and 5-inch howitzers and most of

the ordinary wagons that accompany an army in the field.

Timbers of bridges for carrying heavier weights, e.g., gunsof position, should be calculated {see Part II.).

The following approximate dimensions for spars of unsdected

timber are necessary for carrying infantry in fours crowded :

For bays of 15 feet—Road - bearing transoms, mean

diameter, 10 inches. Baulks (six), mean diameter,

7 inches.

For bays of 12 feet— 1 inch less than above will suffice.

Other timbers not affected by length of bay :

Ledgers andhandrails,

meandiameter, 4 inches to 6 inches.

Braces and ribands, 3 inches at tip.

Legs, trestle, mean diameter, 6 inches.

These dimensions are calculated for spars of rather weak

wood, such as larch, and allow for a factor of safety of three.

Five road-bearers are enough for selected spars.

Camber. 149. The roadway is generally constructed with a sHght rise

towards the centre of the bridge to allow of subsequent settle-

ment ;this is technically called the camber, and should be about

-^\ of the span.





60 CHAPTER XIV.—BRIDGES.

Placing

and

bracinn;

trestles.

Three-

legced or

tripod

trestles.

the ledgers should be close to the butts, so as to take the mud;

for a rocky bottom they should be high enough up not to

touch.

Square lashings {see Sec. 129) must be used. The braces

are put on the frame with both butts and one tip on the

same side, the second tip on the reverse side ; their butts

can be lashed simultaneously with the ledger and transom.

The frame must then be squared by testing the diagonals,

measuring from the centre of the ledger lashing to the centre

of the transom lashing on the opposite leg, and the frame must

be adjusted till these measurements are equal. The braces can

then be lashed at the tips and crossing point.

If the timber is weak both legs and transom can be doubled.

Ledgers and diagonal braces can be of light material, as little

strain is brought upon them, but they should be well lashed.

When the water is very shallow the trestles can be carried

out and placed by men working in the water. When the water

is too deep for this they can be carried on to the bridge and

lowered feet first down inchned spars to their final position,

or taken out on rafts and by means of guys taken to shore

tipped up into position.

Two-legged trestles are kept upright by lashing the road-

bearers to the transoms and by cross-bracing from each trestle

to its neighbour {see PI. 49, Fig. 1), the nearest trestles to the

banks on either side being rigidly connected thereto by light

spars lashed to the tips of the legs and to bollards on the bank.

These light spars are put on before the trestle is launched,

and help to get it into position, they also serve as handrails

when the roadway is placed.

153. PL 51. Fig. 1. shows three-legged trestles, two of which

are required for the support of a single transom ; to make them,

it is best to lash two legs together by a sheer Ipshing, open them

out, and then add the third leg or prypole (see Fig. 2) ; the

trestle must t' en be up-ended, the feet placed on the angles of

an equilateral triangle with sides of about half the height, and

thrê light ledgers attached.

The advantages of tripod trestles are that they utilise light

material, will stand without bracing, and admit of more ready

adjustment, raising or lowering, of the roadwây than either



TRESTLES

PLaJîS]

.OS Wel («r k Gr«h««ii. Lflf U rte^^Ôon







BRIDGING EXPEDIENTS.

Jî^.1.

If^î.os.

Opposite pn^ 6/.



CHAPTER XIV.—BRIDGES. ol

of the other forms ; they are, however, unsuitable for aa

uneven bottom, and extremely difficult to place, excepting by

actually carrying them into position. They are usuallyplaced from rafts when working over water, and their legs must

be weighted.

154. Fig. 3 shows a four-legged trestle; it is made of two Four-

frames similar to two-legged trestles, locked at the transoms, legged

and connected by short ledgers at the feet. One frame must trestles,

therefore be made narrower than the other. The inclination

of the legs should be such that the breadth of the base on which

the trestle stands should not be less than half the height. The

legs

mustalso have an outwards splay of

|.Four-legged trestles can be made of fairly light material, and

will stand without bracing. They are consequently useful

for small bridges of two bays,' requiring one central support,

and as occasional steadying points in a long bridge of two-

legged trestles.

When a carpenter's tools are available, trestles may be

made with iron fastenings ; they are more durable than those

made with rope. Figs. 4 and 5, PL 51 are examples. Fig. 5 is

especially useful when only light timber is available.

155. Communication may be rapidly established across a gap BridiJing

by the method shown in PL 51, Fig. 6. In Fig. 6 two spars expe-

are rested about their centres on the transom of a narrow <lients.

light trestle and launched across. The transom should be

lashed at such a height that when the trestle is inclined

forward so as to land the tips of the spars on the opposite

bank, the transom will be on a level with the two banks.

Planks can then be laid on the spars to form a foot bridge.

156. In PL 52 are shown various expedients which can take Sub-

the place of regularly constructed trestle bridges. Fig. 1, a ^titutes

roadway laid on carts.for trestle

Fig. 2, piers of crib work. This is a specially useful form of " ^^^*

pier when timber is plentiful and other stores deficient. If

used in water a tray should be formed in the bottom of the

crib, which latter can be towed into position, weighted with

stones and sunk.

Fig. 3, small gaps crossed by means of brushwood, in the

form of gabions or fascines.




Fig. 4 shows a method of roughly trussing a log, frequently

used in Canada.

Floating Bridges.

157. In selecting a site for a floating bridge it should be

remembered that the bed of the river should afiord good holding

ground for anchors if required.

The use that can be made of islands to economise material

should be noted.

Koad\>ay. 158. The roadway of floating bridges is similar to that

already described in Sec. 141 ; wide roadways are preferable

to narrow ones, on account of their great steadiness.

Buoyancy. 159. Each pier must have enough available buoyancy to

support the heaviest load that can be brought on to one bay

of the bridge. No extra allowance need be made if the load

is live.

The length of the piers should be at least tw4ce the breadth

of the roadway for the sake of steadiness, and they may be

connected together at their ends by tie baulks or lashings.

The ivaterway between the piers should never be less, and

should if possible be more, than the width of those piers.

Floating piers may be made from specially constructedpontoons, boats, casks, or timber rafts ; inflated skins, or

anything that wîll float, may have to be resorted to on emer-

gencv.

Boats. 160. Open boats should not, except in sluggish water, be

immersed deeper than within 1 foot of the gunwale, and a

still larger limit of safety wall be required in rough water or a

violent current. They should be placed in bridge " bow on"

to the current, and slightly down as the stern ; or if the

river is tidal they must be placed alternately bow and stern.If the boats be not each buoyant enough to form a pier,

they may be used in pairs (Fig. 2. PL 53). The sterns are

lashed together, and the spars AA^ BB| are held over the side

four 2-inch ropes at AB, CD, CiDi, A,Bi, are passed under the

boats and secured to the poles, and four double ropes are

passed round the latter at the same points and cross over the

boats ; these ropes are racked up tight. Crosspieces, MM, are

then lashed to the poles and thwarts, and blocks on the thwarts



I'Uilf. S3

BOAT PIERS

^^.;.

^^j^

SexitLon. Jl.JB.

JÔ/.Z.

^^•10^

3fiddle^ êearv

W^Thj/^'ccyV

6. B 05. W«ller46fah«m.L'* Lirfto,Lon«Jon.

Opposite' pcLge 6Z





d

M

^,1



Plate54

CASK PIERS

rtavruda

SlUL^S

-^F3:3ir

^rTvrrvfIf-

^:^l 7^

Szde JElevaJturn. 2njg 8 ^^-^

Pg^"^

^SS.Z.05.Welleri Graham. L'* LirhoLondon




at EE support the saddle beam, which is lashed to the thwarts

and to the stern rings of the boats.

Few boats, with the exception of heavy barges, are strong

enough to allow of the baulks resting on their gunwales.

A central transom should be improvised, which can generally

be done by resting a transom on the thwarts, and blocking them

up from underneath, thus bringing the weight directly on

to the kelson. This arrangement is shown in Fig. 1, PI. 53.

161. The available buoyancy of a boat may be (most simply) Buoyancv

determined by loading it with unarmed men to such a depth of boats,

as is considered safe, usually within 6 inches of the gunwale

in sluggish streams and 1 foot in rapid, and multiplying this

number by 160. The result gives the available buoyancy in

pounds.

1 62. The usual method of forming a number of large casks Piers of

into a pier is shown in Figs. 1, 2, and 3, PL 54. The casks are ca»iks.

laid bung uppermost, and Hned, two baulks technicallyknown as

gunnels (GG) are placed over the ends, and the slings (SS)

are secured under the ends of the casks to - the gunnels.

Between each pair of casks, on each side, a brace is secured

on the shng, and is then led round the gunnel ; the opposite

braces are crossed and secured again on their own side.

A knot must be made as shown near the standing end of

the braces to prevent tbe crossed parts shpping. Care must

be taken that the braces are pulled taut ; this is best done

by rocking the barrels, at the same time hauling in the

slack. For large piers the shng should be 2J-inch to 3-inch

rope, the braces can be of IJ-inch rope. (For a detailed

description of this method, see Part II.).

163. Fig. 4 suggests a method useful for smaller casks.

Small piers of three or more casks, aa, bh, cc, being made asabove described, and subsequently united by two large

gunnels, X, X.

164. Figs. 5 and 9, show another method useful for medium-

sized casks. The braces are first fastened to a gunnel and

stretched out perpendicularly to it ; the casks are then placed

in two rows, end to end, on each side of the baulk and over their

own braces. On the casks are laid two gunnels, loosely lashed

together at the ends and at one or two intermediate points,




the distance between them being less tlian a bung diameter,

the braces are then secured to the gunnels by two round turns

and two half-hitches ; the lashings connecting the gunnels

are then racked up, and finally the two at the ends are secured

to the underneath baulk by lashings, which are also racked

up taut. Other methods can be readily devised according to

the material available, e.g., the cask can be completely

enclosed in a wooden framework, the parts of which are

lashed or nailed together {see Figs. 6, 7, and 8.

Tie baulks. 165. Piers of casks when in bridge should always be rigidly

connected to each other at their ends by tie baulks, which must

be lashed to both gunnels of each pier; the roadway baulk?

can then be laid, without lashing if rectangular ; they should

rest on both gunnels of each pier.

If, however, the baulks are round, or there is likely to be much

sway on the bridge, and especially for animal traffic, it gives

additional security to lash, at any rate, some of the baulks

both to each other and their overlap, and also to the gunnels.

Headless casks must be enclosed vertically in a specially

prepared framework.

To form 166. To form a raft, the logs should be placed side by side,

a raft thick and thin ends alternating ; they should then be strongly

secured with rope, and, if possible, by cross and diagonal pieces

of timber fastened by spikes or wooden trenails ; or the logs

can themselves be connected by dogs.

If a raft is to be used as a pier in a bridge, it will frequently

be necessary to place the logs in two layers, to avoid obstructing

the waterway. A central raised transom must be used.

The up-stream end of the raft may, with advantage, be slightly

convex.

Rafts are most easily put together and manipulated in thewater.

Anchoring 167. Anchors are of various weights. For ordinary bridge

of bridges, work 5G-lb. anchors, with a reserve of 112-lb. anchors, will

generally suffice for moderate streams.

The cables are generally of 3-inch rope. The length of cable

" out " should be ten times the depth of the stream, and rarely

less than 30 yards. The cable is attached to the ring of the

anchor (PI. 55, Fig. 1) by a fisherman's bend ; a buoy should



I



I'/'rt^> 55.

ANCHORS

^^.^.

CrownX—

IFigr.S

Fi^.^.

5/86.S 05.Wwlertirfltism.L" Li>t>ci,Londoo




be attached to the anchor by a buoyline of l-inch rope, fastened

to a ring of the buoy by a fisherman's bend, and round the

crown of the anchor, with a clove hitch split by the shank,

and two half-hitches round the shank. The use of the buoy is

to mark the position of the anchor and serve as a means of

raising it.

As a rule there should be an up-stream and down-stream

anchor to every second pier of a floating bridge.

If anchors are scarce, one may be made to serve for two

piers by attaching two cables to it on the down-stream side

of the bridge, as shown in Fig. 2.

Care must be taken before heaving an anchor overboard to see

that it is carefully stodced.Timber raft« and cask piers being, as a rule, a greater strain

on anchors than boats or pontoons.

In d very rapid current, anchors can seldom be trusted.

The bridge must then be secured to a hawser stretched across

the river " up-stream.*' Wire rope is convenient for the purpose

(Fig. 3). Short bridges can be kept steady by cables stretched

from the piers to the banks, up and down stream (Fig. 4).

168. The following are substitutes for anchors : Makeshift

Twoor more pickaxes lashed together. anchors.

Heavy weights, such as large stones or railwav irons

the latter are best when bent.

Nets filled with stones— remarka^bly effective on rocky

bottoms.

169. X bridge can be formed by booming ov.t, i.e., the head Methods

of the bridge already constructed is continually pushed out o''^"o?''^'ng

into the stream, fresh materials being added at the tail. This ?°^^^^°

method economises the distance the materials have to be BoomiiT^

carried, but necessitates a certain number of men working out.

in the water, and cannot be used vrhen the banks are steep,

and there is deep water close in shore, as for instance, in the

case of a wharf wall.

In forthing up. material is continually added to the head Forming

of the bridge, the tail being stationary. This method is up.

uninfluenced by the nature of the banks, no men being required

to work in the water. Its only drawback is the distance the

roadway materials have to be carried.

(5289) T,



GG CnArTER XIV.—P.TIIDGES.

Bafting.

Swinging.

Forming

cuts.

Protection

of floating

bridges.

Passage of

heavy

artillery.

Passage of

arms and

ammuni-

tion.

Ferries

and flying

bridges.

In rafting, the bridce is put toiretlipr in difTeront pcrtionp or

rajt? along the shore, each raft consisting of two or morn piers,

which rafts are successively warped, rowed, or towed into

their proper positions in bridge.

This method has the advantage that a large number of men

can be employed simultaneously ;and if secrecy b?5 an object,

the various portions can be constructed at some distance

from the eventual site of the bridge, and a favourable oppor-

tunity seized for its construction.

In swinging, an entire bridge is constructed alongshore,

and then swung across with the stream.

A long bridge can be constructed by a combination of two

or more of the above methods.

If a bridge has to remain down for some time, arrangements

must be made for the passage of the river traffic, which can be

done by having two or more rafts, at the centre of the bridge,

arranged for " forming cut " as required ; or the two halves

of the bridge may be swung, to afford the requisite passage.

170. Arrangements must always be made, up-stream, for

the protection of a bridge from damage by floating substances,

either by a boat patrol or by stretching a net or some inter-

cepting obstacle acioss the stream.

171. If heavy siege artillery has to be passed over a broad

river it will generally be most economical of m.atcrial to con-

struct the bridge of only sufficient strength for the ordinary

traffic, and to warp the guns across on rafts constructed of

sufficient strength for the purpose.

172. To keep rifles and am.munirion dry when men swim

across a river, small rafts can be made of w;iterproof kitbags

filled with straw, blown-out ma'âks (water-skins), cooking

kettles or any similar vessels, which should be placed mouthdownwards.

The simplest form of permanent ferry consists of ropes

stretched across the river by means of which rafts can be

sheered or hauled backwards and forwards from bank to bank.

If it be not convenient, for the sake of traffic or other reasons,

to stretch a rone across the stream, recourse may be had, if

the current is rapid and regular, to a flying brid<7e, which is one

in which the action of the current is made to move a boat or



N



P(xrf€.ê.

FORDS & FLYING BRIDGES

^ Stream^

^^*^ tP- 7^^-^.y

VMIerii&r»t>a« 'C* li>(M.Lon(ton







JPlccte.51.

KITCHENS.

riy.z Seotvo

RECTANGULAR

CvoJcj f»f V'.ft-i BROAD3A? ftten. ARROW

COVERED KITCHEN

\f^'\\ Tr^.^.i'^:^!^

Ti^.5

WeU«r«,«ireh««.L'* liH>O.U>«««r





J^lat^5ti

GRIDIRON KITCHEN

I'Zjr^.?.

up!'^^ a^/:r ii

A^

.^f1

p

^!-f-'?---:-jf-*'---^-'ii

1—

/\ /\ /\ /\ /\ /\ / \J\^rervchy 36 '^2''X 7 'S oi&^pff

JPVy.^. ALDERSHOT OVEN

J^z^.S

8 OSwelter &€r«h4n.L" LitftoLondon

7h foZlcnvplate37.













CHAPTER XV.—CAMPING ARRANGEMENTS. 69

Mess tins can be arranged similarly, but in their case not Mess tins,

more than eight should be used together.

178. The simplest form of a field oven consists of a hearth Field

sunk below the ground surface, with, an arch formed by a hurdle o^^^ns.

or sheet iron {see ?1. 60). The two gable ends are formed

with sods. The whole of the interior of the oven is well

plastered with cowdung and clay. The hurdle, well plastered

on the outside with cowdung and clay so as to leave an arch

when it burns away, is covered with earth from the excava-

tion. The entrance to the oven is closed either by a hurdle

plastered with '^]ay or simply by sods.

This oven is specially suitable for making bread, and will

bake for about 150 men at a time.

Figs. 5, 6, and 7 show an oven with a flue underneath an

iron hearth. The oven is first heated by lighting a fire inside

it, and this is afterwards raked out and pushed into the flue

below to maintain the heat. It is a very useful oven for

baking or keeping men's dinners warm. The service oven,

Aldershot pattern, should be fixed up without the flue, but

placed on a prepared flattened site.

Latrines.

179. Latrines should be made as soon as troops arrive on Latriues.

the ground ; a small shallow trench will suffice for one night

and should be invariably filled-in in the morning, before the

troops march oS. In standing camps latrines may be made

with seats, the seat being a pole (see Figs. 1 and 2, PI. 61);

additional comfort may be given by adding a top pole

to form a back, as shown. Other forms are shown in

Figs. 6 and 7.

In order to keep out flies latrines, where practicable, should

be closed in and made as dark as possible.

Latrines should be constructed to seat if possible at least

5 per cent, of the troops, 1 yard per man being allowed.

The trenches must be narrow and deep to prevent the contents

being blown about. When natives are employed special

latrines for them are necessary.



70 CHAPTER XV.—CAMPING ARRANGEMENTS.

It is very important that a couple of inches of the driest

earth obtainable should be thrown over the soil twice daily;

this, if carefully done, will prevent all smell and tend to

prevent flies collecting. The earth may be dried by pihng it

close to the trenches of the field kitchens. Lime or charcoal

may also be used to deodorise the soil in the trenches.

On leaving camp the site of latrines should be carefully

marked.

Too much care cannot be bestowed in selecting the site of the

latrines; since flies are very active agents in propagating

diseases, latrines must be placed well awây from cook-houses.

Care must be taken that no filtration from them may reach the

water supply.

Water Supply.

Wator 180- Each man requires for drinking about 3 to 4 pints per

supply. diem; for drinking and cooking, 3 to 4 quarts; for drinking,

cooking, and washing, 3 to 4 gallons.

Each horse requires for drmking 5 to 10 gallons, according

to work andchmate, soft water being the best ; for cleaning,

6 to 8 quarts (which may be salt). Each mule or ox drinks

G to 8 gallons ; each sheep or pig 6 to 8 pints. These are

minimum quantities.

Horses drink about I J gallons at a time.

In calculating troughing, allow each horse five minutes

at the trough.

^.B.—See also " Combined Training," 1905, Sec. 43.

One cubic foot of water = G^ gallons (a gallon = 10 lbs.).

Pleasure- 1 81. The rough average }4eld of a stream may be measured as

iiient ot follows :— Select some 12 yards or 15 vards of the stream..; -.1 .1 ...here the channel is fairly uniform, and there are no eddies.

Take the breadth and average depth in feet in three or four

places. Drop in a chip of wood and find the time it takes to

travel, say, 30 feet. Thus obtain the surface velocity in

feet per second. Four-fifths of this will give the mean velocity,

and this multiplied by the sectional area in square feet will

give the yield per second in cubic feet of water.

quantity

ivquiivd

yield.



rCucteGJ

LATRINES

S' 3 rr

-^ . 4-. M 38Z

ss

J-^g.5.

Section^ 6/./^.

8.0S

Opposite 70






The source of the water supply should be carefully in- Source,

vestigated, and measures tiiken to prevent the pollution of the

water en route to the drinking supply.

182. In the field the supply is usually obtained from sources

which are at once available, such as streams, ponds, or existing

wells. In default of these it may be necessary to sink wells

and make reservoirs.

Surface springs should be sought for in hollows, at the Surface

foot of hills, where the earth is moist or where the grass is springs,

unusually green, where the thickest mists rise in the mornings or

evenings, &c.

183. If the supply be from a lake, pond, or stream, separate Protection

watering-places for men and animals must be marked out and <^t" tlie

sentries posted. Stagnant water, as in a pond, is apt to be ^^^^^^^ ^'

contaminated by large numbers of animals going in to drink

and even in a stream, when many animals are drinking, those

below get foul water. If possible, therefore, the water should

be drawn from the source and run into drinking troughs;

these are best made of canvas or of boards ; but trenches lined

with puddled clay answer the purpose.

1 84. The overflow from the troughs must be carried ofi withthe surface drainage. The sites of the troughs should, if

possible, be paved and drained for a width of 10 feet, and should

be so arranged that the animals may move to and from them

without confusion or crowding, arriving from one direction

and leaving in another.

Each horse occupies laterally 4 feet ; if possible, all the horses

in a camp should be able to be wâtered in an hour.

When troughs cannot be made, the banks should be cut

down, and a hard bottom formed on the ramp to prevent theanimal from sinking in. A barrier may be placed in the pond

to prevent them from going out too far. The water should not

be less than 5 inches or 6 inches deep where beasts are to drink.

185. In a stream the men should draw wâter above the place Supply

for the animals ; while washing, &c., should be done below, ^'"'^"^

and drainage should enter below the others as far down stream ^'**''^"^*-

as possible.

Barrels sunk in the bed of a small stream afford convenient

dipping places.



from

spring


Supply 186. If the supply be from springs, each springhead should be

opened up and surrounded by a low puddled wall to keep out

surface water. Casks or cylinders made of brushwood, like

gabions, make good linings for springs. After they are placed,

puddled clay may be worked down between the banks and the

cask or cylinders. The overflow may be received into a suc-

cession of casks or half barrels (which may with advantage

have their insides charred) let into the ground close together,

the overflow from the first passing into the second, and so on;

or deep narrow tanks with puddled sides may be constructed

to catch the overflow.

Water from small ponds and shallow wells should be avoided,

if there be a choice.

P^- 187. The lift and force pump is in most general use in the

service. It is worked by two men. It can lift water from a

depth of 20 feet to 28 feet, and force the water to a height of

60 feet from its former level, dehvering 12 gallons per minute.

Purifying Water.

Boiling. 188. The best method of purifying water is by boiling.

It gets rid of temporary hardness, renders dissolved organic

matter harmless, and when carried out effectually practically

destroys all micro-organisms. The water should be kept at the

boil for at least five minutes.

Boiled water should be aerated before use. This can be done

by passing through a sieve. Improvised methods can be

arranged according to the means at disposal. Empty biscuit

tins pierced with small holes suspended over a storage tank

do very well for this purpose.

Care is necessary to prevent the addition of fresh impurities

during aeration and distribution,

riltraiion. 189. As it is not always possible to provide means of boiling

water on a large scale, filtration must be resorted to.

Formerly mechanical filtration only was attempted and a

clear sparkling water was considered good. Efforts are now




directed to remove meclianical and chemical impurities as

well as micro-organisms. Several filters have been brought

before the public, all claiming to effect these purposes. The

type most familiar is the " Berkefeld " filter. These filters,

if treated with care and strict attention to detail, work satis-

factorily. Their chief defect is a very slow dehvery when water

containing a large percentage of suspended matter is used.

The porcelain candles become almost impervious when coated

with fine mud and constant cleaning is necessary. This,

however, is an easy process.

Dirty water should be strained before filtering. A good

method is to tack a sheet on to a wooden frame so as to form a

bag or basin;put a couple of handfuls of wood ashes in the

bottom, and then pour on the water, allowing it to percolate

into a receptacle beneath.

190. Chemicals are sometimes added either : {a) to precipitate Addition

suspended matters;

[b) to remove hardness or;

(c) to oxidise ^^

organic impurities, {a) Muddy water may be cleared by adding ^ ^^^^^^^ ^•

alum. Six grains of crystallised alum per gallon is sufficient.

It should be added some hours before the water is required.

[b) Water can be softened by the addition of Hmewater for

drinking and carbonate of soda for washing purposes. The

latter is unsuitable for drinking water as it gives an unpleasant

taste, (c) Permanganate of potash (Condy's fluid) removes

offensive smell from water and to some extent oxidises dissolved

organic matter. It should be added until a faint tint remains

permanent. It has not a disagreeable taste.

Shelters and Huts.

191. Bivouacs are but seldom resorted to except in the neigh- Bivouacs,

bourhood of an enemy, when miUtary rather than sanitary

considerations are of primary importance. The following are

the chief points to borne in mind in determining the sites

for bivouacs :

In the presence of an enemy, tactical considerations, e.g., Choice of

favourable ground for defence in the event of attack, conceal- ground




ment, facilities of protection, and consequently, economy

in outposts are of the first importance. The comfort of the

troops, in conjunction with sanitary conditions, is the next

consideration.

A good water supply is essential, but considerations of

safety may necessitate a camp or Livouac being placed at

some distance from it. Other points to be considered are the

facilities which a site offers for obtaining shelter, fuel, forage

and straw.

The site for a camp or bivouac should be dry, and on grass

if possible. Steep slopes should be avoided. Large woods

with undergrowth, low meadows, and newly turned soil

are apt to be unhealthy. Clay is usually damp. Ravines

and watercourses are dangerous sites, as a sudden fall of

rain may convert them into streami.s.

If the occupation is to be of a permanent nature, as

in investment warfare and the defence of strategical points,

the men ought to be hutted.

Tem- 192. PI. 62 suggests methods of forming simple shelters,

porarv Yis. 1. Two forked sticks driven into the ground with a pole

restmg on them;

branches are then laid resting on the pole,thick end uppermost, at an angle of about 45"^, and the screen

made good with smaller branches, ferns, &c.

A hurdle may be supported and treated in a similar way.

Fig. 2. A waterproof sheet, blanket, or piece of canvas

secured by poles and string.

Fig. .3. A tent (Tabri for four men, formed with two blankets

or waterproof sheets laced together at the ridge, the remaining

two blankets being available for cover inside.

Fig. 4. A wall of straw or reeds nipped between two pairsof sticks, tied together at intervals.

Figs. 5 and 7. Sentry box for standing camps.

When no other materials than earth and brushwood are

available, a comfortable bivouac for 12 men can be formed

by excavating a circle with a diameter of 18 feet, or there-

abouts, and piling up the earth to form a wall 2 feet or 3 feet

high. The men lie down, like the spokes of a wheel, with their

feet towards the centre. Branches of trees, or brushwood stuck

into the wall, improve the shelter.

shelters.



^Wêx^

BIVOUACS.

:Fzff.i. SFig.Z'.

STteZce?^ Terut

:Fcgr.3.

^^^'

^rv:>7ft. of T-ourLdySooo

3. as







Plojte 63.

HUTS.

^7ânrk4s.

THATCHING

?ra^

siee i .OS.





Plate ^4

HUTS

\^^ : ^'.'n < ' -"',f-, f I

-* ?-, »

'-r^

'^'^

pieces

-?'"Y<y. ^.

JLoq. SuJ(>

J±^Z,ou7y

SIB9. a.os. WcilerAGratiam. LH Litho. London.




193. The materials of which huts are made depend upon the Huts,

resources of the locality, and are principally brushwood, logs,

straw, reeds, clay, turf, and stones.

The best form of hut is generally rectangular in plan, with Plan,

sufficient width for two rows of beds, and a passage down the

centre, but, where the material available is of small size,

one row of beds may be provided, or the hut may be made of

circular form. A width of at least G feet should be allowed for

each row of beds, and the passage may be from 2 feet to i feet

wide.

The accommodation may be calculated on active service Accommo.

at one man per foot in length of the hut, when there are two ^^^ô"-

rows of beds, and one man to every 2 feet when only one rowon beds.

Fig. 1, PI. 63, shows how the ordinary 6-foot hurdles maybe arranged to form a hut. A fascine at the ridge, with thatching

of straw, reeds, &c., may be used as roofing.

Hurdles may be made of special dimensions for hutting Hurdles,

purposes. Fig. 2 shows how a hurdle 10 feet long (measured

on the curve) may be made into a hut. The hurdle is constructed

on a curve slightly flatter than that it is intended to have,

so that it is necessary to spring it together to get it into position.

It is then secured with pickets, and covered with sods, or daubed

with clay in the manner described in Sec. 195. The ground

forming the floor of the hut may be sloped as shown before

putting on the hurdles.

Hurdles for hutting purposes should have the ends of the

pickets cut off as close to the web as possible, so as to leave no

gaps between them.

194, When brushwood of 2 inches or 3 inches diameter and Brush-

14 feet or 15 feet long is available, a hut for a double row ofwood,

beds may be made as in Figs. 3 and 5.

The section of the hut being decided on, is laid out on the

ground ; from this the length of the rafters is obtained.

Each side of the roof is then made separately on the ground

as follows :

Poles of 2 inches to 3 inches diameter are laid on the ground

parallel to each other, from 18 inches to 2 feet apart, as aa,

in Fig. 4, PL 63. These form the rafters. On the slope of the




ixiaterial.

Passa*.

rafters, and at right angles to them, hght rods or laths, hh.

from -J inch to I inch thick are laid, the uppermost one being

at such a distance from the bottom of the poles as will allow

the frames^ when made, to lock at the desired height above th^^.

ground, the lowermost one being within a few inches of the

bottom, and the interval between being divided according to

ll-e length of the thatching or covering material. The distance

apart of these laths should be slightly less than half the length

of the covering material, so that the latter may be supported

i.t three points. With good wheaten straw the !nterv:il maybe from 12 inches to 1^ feet. At each point of crossing the

laths and rafteis are secured by a short length of one strand

of spun yarn, and the frame thus made is afterwards stiffened

by diagonals lashed underneath.

The roofing material, which may be unbroken straw, rushes,

long ferns, &c., Is now put on. Commencing at the bottom,

a layer 4 inches or 5 inches thick is equally laid over the three

lowest laths, ears or tops downwards ; it is here secured by

a light rod or thatching piece tied with spun yarn at intervals

of 2 feet or 3 feet to the second lath from the bottom. A second

layer is now put on one lath higher up, and is secured in a

similar wây to the third lath from the bottom, and so on

until the top is reached ; the last layer projecting over the

top lath, so that when the frames are locked the ends may

be twisted together to keep out wet (Fig. 6, PI. 63). Whenboth frames are ready they are raised and locked, as in Fig. 3.

Forked uprights and a ridge piece may be added to stiffen the

roof.

Each side of the roof may be made in one piece, or if large

and inconvenient to move, in two sections. The ends of the

laths should project about 2 feet beyond the extreme rafters,

and are supported by the framework forming the Gable ends,

Fig. 5. The latter are made and thatched in a similar way to

the roof, and simultaneously with it, an opening being left

for a door.

In order to give additional headway, the passage may be sunk

as in Fig. 3, with steps at each end, the earth being thrown

to the eaves as additional protection, and to give more head

room when lying down. In very cold weather the whole

interior of the hut may be excavated, fireplaces constructed




as in Fig. 1, PI. CA, and, if the rafters be strong, some of the

excavated earth may be thrown on to the top of the roof,

a collar tie being added to strengthen it.

Huts may also be thatched by forming the straw or grass into Panels.

panels. The straw in moderately thick layers is doubled

and nipped near the centre between two rods, one above andone below, which are tied tightly together at the ends and at

intervals of about 6 inches.

The panels formed thus are tied on to the roof, being placed

so as to overlap hke large slates.

195. Walls may be constructed of ivattle and daub, i.e., Wattle

continuous hurdle work daubed over on one or both sides with «^f^ daub

clay, in which is a proportion of any fibrous substance, such^'^*^'^'

as straw, grass, horse hair, &c., chopped into short lengths

to prevent the clay cracking and opening as it dries. This

mixture, which should be kneaded into the consistency of a stiff

paste, should be worked in with the hands. The sides should

be strutted at intervals to resist wind, and the roof mav be

carried on a ridge pole, which may be strengthened by uprights

in the centre, Fig. 3, PL 64.

196. When timber is abundant, log huts maybe constructed Log huts,

as shown in Fig. 4, PI. 64. No fastenings are required beyondsome trenails (wooden pegs) to secure the rafters to the top

logs. The roof may be made as already described, or the

covering material may be of slabs of wood, bark of trees, &c.

Bark may be got off trees in large strips by cutting roundthe tree with a knife at intervals, say, of 4 feet ; then cutoff

width required, and beat with a flat piece of wood to detach

the bark from the tree.

197. When straw is issued for the troops to he upon, it may Straw

be made up into mats in the manner shown in Pis. 65 and 66. "ât?.

To make the mat shown on Fig. 1, pickets are driven into

the ground, the outside pickets being at a distance apart

about 6 inches less ttan the width of the required mat. Acrossbar, AB, is fixed about 2 feet from the ground. Several

lengths of spun yarn are then taken and made fast, about their

middle, to the crossbar, AB, at a distance of 5 inches or 6 inches

apart, and their ends made fast to the bar, CD, and to the

other pickets, as shown in the figure. Handfujs of straw



70 CHAPTER XVI.—HASTY DEMOLITIONS.

rather longer than the width of the mat are taken and pushed

in between the yarns, and the bar, CD, being alternately

raised waist high and depressed to the ground, and passedinside and outside the end pickets, so as to form a hitch.

Finally, the sides of the mat are trimmed to the right size

by a sharp pair of scissors or a knife, and the yarns finished

off at either end with reef knots.

Straw The mat shown in Figs. 2 and 3 is formed by makingropes. straw ropes and interlacing them on pickets driven into the

ground. If the straw ropes are carefully made, this makes a

more durable mat than the previous one. (PL 67.)

CHAPTER XVI.—HASTY DEMOLITIONS WITHEXPLOSIVES.

Explosives.

Explosives 198. The service explosives available for hasty demoHtions

th^Tlrf"in the field are guncotton, gunpowder, cordite

;guncotton being

specially carried for this purpose. Dynamite may also some-

times be obtained locally.

Coin- For hasty demohtions guncotton is by far the best of theparison of service explosives. Its chief advantages over gunpowder

Guncotton^^^ *^^^ ^^^ equivalent effects a guncotton charge takes up

and much less room, and does not require the same amount of

powder. tamping* ; it is therefore much more easily and quickly placed

and fired, which is an important point in hasty demohtions.

* "Tamping" is covering tha charge over with earth or other material

so as to confine the gases at the commencement of the explosion, and thus

develop their force more fully.







Plaix.66,

MAKING STRAW MATS

Wel'erA Graham L^r Litho,London.

To foUvyv j>hx±c. S5





^Zcote, 67

MAKING STRAW ROPE

i •S. Welier fc Graham. Lff Lirti6.Loodon

Tc fellow pLocte 6^





CHAPTER XVI.—HASTY DEMOLITIONS. 79

Guncotton is also safer in transport and handling.

Cordite and dynamite are nearly as powerful as guncotton, Cordite

and have the aboveadvantages over gunpowder,

butare

not

^"^

so safe m transport.

Where a lifting and shaking effect is required, gunpowder is

best.

Where a cutting or shattering effect is required, which is

most likely in hasty demolitions, guncotton, cordite or

dynamite are best.

Guncotton.

199. Guncotton, if steeped in water, will absorb about ProporMes

30 per cent, of its weight. ^^ ^^'©t

Wet guncotton does not ignite easily, and requires the ex-^^"^^^^ °"'

plosion of a very large amount of detonating substance, such

as fulminate of mercury, in contact with it to detonate it.

Dm guncotton will not detonate in the open in small quantities Properties

if a light be set to it, nor if a bullet strikes it when not heated. °^ ^^^

It will detonate if it is struck between two hard substances.^"^°°

If dry guncotton, especially when finely divided in the shape Sensitive

of fluff, becomes heated in any way (through friction or the T^^Î^.

heat of the sun) it is much more sensitive to percussion.

If a small quantity of detonating substance such as fulminate Means of

of mercury be exploded in contact with dry guncotton, it will detonating

detonate with great violence, and also cause the complete^^^

detonation of any wet or dry guncotton with which it is in^^^^^

contact.

The explosive force of wet guncotton is slightly greater than

that of dry.

So that for safety in transport, &c., in the field, the bulk of Carriedguncotton is carried and used wet in the shape of " slabs^ ^®^-

For detonating this, dry guncotton is also carried in the shape

of small discs called " primers''' The following table gives Primers,

the dimensions of the slabs and primers for land service :

Slabs are issued in two sizes, about 6 inches square, weighing

1} and 14 lbs. respectively.

Primers are also issued in two sizes, weighing 1 oz and 2 ozs.

respectively.



80 CHAPTER XVI.—HASTY DEMOLITIONS-

The slabs have two holes in them, one to fit the 1 oz. primer

and the other the 2 oz. primer.

Cavalrypioneers carry special 1 lb. slabs.

Primers are carried dry in airtight tin cyhnders.

Use of wet For auger holes and for necklaces round timber, dry gun-

and dry cotton primers form the charge. Otherwise the charge is

S"^^^"'^"- always of wet slabs.

Details. The slabs can be cut without danger with a sharp knife or

saw, care being taken to press the guncotton between boards

whilst it is being cut to prevent it flaking away. There is

a special clamp in the R.E. equipment for doing this. The

guncotton should be kept damp.

]\reans of A charge of wet guncotton is detonated by means of the

detona- explosion of a dry primer in close contact with it. The primer*'^®°'

is exploded by means of a " detonator," the detonator is

detonated by means of either " safety " or " instantaneous

fuze," which is lit by a fusee or other means. (For details

of detonators, fuzes, see Sec. 205 and onward.)

Tinpro- If dry primers are not available, a piece of wet guncotton

rised can be dried hy exposure to the sun, and used instead,

primer.

Connect. 200. A charge is connected up for detonation as follows :

ing up for '£\iq fuze (safety alone or safety wdth instantaneous) is cut

to the required length. The end to be ignited is cut on a slant

to expose as much of the composition as possible.

The end to be inserted in the detonator is cut straight across.

The straight cut end is then gently inserted into the open

end of No. 8 detonator, from which the paper cap has been

torn. This end of the detonator is then slightly bent (or with

new-pattern detonator, pinched) to make it grip on the fuze

and so prevent its being withdrawn.

(Cavalry pioneers carry detonators with a short length of

safety fuze ready fixed, the fuze having a piece of quickmatch

added to the end to facilitate lighting.)

The primer having been placed in close contact with one of

the slabs of the charge, either in one of the holes or tied to a

slab (see that the primer is dry), the small end of the detonator

is gently inserted into it so as to fill the entire length of the

hole. If the hole is too large, a piece of paper or grass must

detoiia

tion.




wrapped round the detonator to make it fit tight ; if too

it must be enlarged with the rectifier* or piece of wood, Rectifiers.

not with the detonator.The charge must he in dose contact ivith the object to he de- Arrange-

and all the slabs must he touching each other. nênt of

Where the charge is a very long one, more than one detonator " ^^^S®-

be used.

The charge must extend across the whole length of the object placing of

be cut. charge.

Arrangements must be made to prevent sparks from the

falling on it and so setting it alight instead of detonating it.

For calculation of charge, see Chapter XXI. Amount of

charge.

Gunpowder.

201. Gunpowder is not so suitable for hasty demolitions as Details,

and the larger the grain of the gunpowder the less

it is, owing to its slow burning.

Except the larger grained prism and moulded powders,

are packed in cases, it is usually carried in barrels,

powder being contained in a waterproof bag inside the

Powder is usually fired by safety or instantaneous fuze. Ignition.

A gunpowder charge should be made up in as compact Making up

form as possible, and if sandbags filled with earth are used t!iechargf.

tamp it, the charge should be of the same shape as the sand

A service sandbag will hold about 40 lbs. of gunpowder,

is about as much as a man can carry conveniently.

a charge has to be placed under fire, and the amount is

than this, it should be divided amongst several bags,

required, rather than put into one large one. In this case

one bag need be fuzed.

* Eectifiers arc boxwood implements supplied for enlarging tlie per-

in guncotton primers so as to take the shanks of detonators.

(5289) V




Connet- A gunpowder charge should not, as a rule, be spread evenly

ing up along the whole breadth of the object to be destroyed, but'"'^'*

should be divided up into portions, which may generally be

ignition^^ ^ distance apart of twice the thickness of the object. The

several portions must be fired simultaneously.

In the case of a stockade or fort gate, one concentrated

charge will make a breach wide enough to admit of easy

entrance.

Amount of For the amount of charges suitable, see Chapter XXI.fharge.

Cordite.

Supply. 202. Cordite can be used instead of guncotton or dynamite.

It may be obtained from gun cartridges, and would only be

used where no other explosive is available.

Making up It must be detonated with a guncotton primer, and the

charge. cordite should be tied up in a tight bundle with the primer in

the centre.

The primer being connected up with No. 8 detonator andfuze as described for guncotton.

Its successful detonation is rather uncertain.

Placing As with guncotton, the charge must be in close contact with

charge. the object to be demohshed.

The cordite must be covered up with fresh grass or leaves

to prevent the sparks from the fuze setting it alight, which

happens very easily.

Amount of As for guncotton, see table, Chapter XXI.

charge.

Dyxamite.

Supply. 203. D}Tianiite, where procurable, can be used instead of

guncotton.

For military purposes the only advantage that dynamite

has over guncotton is, that being plastic it is easier to fit into

narrow and irregular holes such as are used for blasting rock.




For demolishing masonry it is not so good as guncottom,.

as its action is even more local.

It cannot be used after exposure to wet, which separates General

the nitro- glycerine and makes it dangerous. properlies.

It freezes at 40° F., and remains frozen at higher tempera-

tures. Frozen dynamite can be distinguished by being

harder than unfrozen, by being more brittle than plastic, and

being of a slightly lighter colour.

Frozen dynamite should if possible be thawed before use.

It cannot be usad when frozen as it will not detonate readily,

though it will explode bv simple ignition.

IT MUST NOT BE THAWED NEAR A FIRE, but by

the warmth of warm water, in some apparatus like a common

glue pot, where the dynamite can be kept dry while surrounded

by warm water not hotter than the wrist can bear.

It is usually obtained in 2 oz. cartridges wrapped in parch- Supply,

ment paper.

It can be detonated by fuze and No. 8 detonator, or by Detona-

fuze and cap. tion.

No. 8 detonator is unnecessarily strong.

When cold weather is likely, dynamite should be buried a Storage.

foot or two underground.

hN

Dynamite Charges.

204. If a No. 8 detonator be used, this is connected up with Connecb-

fuze, as described for guncotton, and the end inserted into one J^g^^P

of the cartridges for about 2 inches and tied in.^^'^^

^

•1 • 11 -1 itjîx means oi

If a commercial cap is used, the straight cut end oi the luze oietona-

having been gently inserted into the mouth of the cap till tion.

it touches the fulminate, the mouth of the cap is squeezed to

hold the fuze in place.

(5289) F 2




The cap, with the fuze attached, is then inserted into one of

the dynamite cartridges almost as far as its length, and tied

into position.

Arr.in2e- For a bore hole for blasting, or an auger hole in timber, as

inent of many cartridges as necessary are inserted, and each squeezedcimrge.

-^^ separately with a wooden rammer {see Fig. 7, PI. 68). Iron

Boreholes, must not be used to ram with, and the ramming should be

gently done.

The cartridge with detonator or cap for firing should be the

last,

ri icing For other charges the dynamite should be tied up in as

.thiirges.

compact a parcel as possible, and placed tight against theobject, the means of detonation being in one cartridge.

All the cartridges of a charge must be in contact.

Hole for Holes for detonators or caps must be made with the rectifier

f-^P- or a piece of wood.

'lamping. The tamping of a bore hole may be sand, clay, or water,

but in the latter case the cap must be kept dry.

Ciiccldite. A new explosive called cheddite is coming into use; it has

about the same explosive effect as dynamite, and has the

advantage of not freezing at so high a temperature. It wouldbe useful in blasting work.

Use under For use under water dynamite and similar explosives should

uater.\jq îed in a waterproof bag {see PI. 68, Fig. 8) .

Means of Detonation and Ignition.

Detonators.

Dctoua- 205. There are two kinds of detonators in the service for

tors for detonating guncotton ; only one will be here described,

gunootton,y^^., that called " Detonator No. 8 for safety fuze "

;the

other, which requires electrical firing apparatus, being beyond

the scope of this manual.

Iso. 3 Fig. 1, PI. 68, gives a section of this detonator. It consists

dcionalor. ^f ^ brass tube painted red, the small end of which, A, contains



PlCLte f'8

HASTY DEMOLITIONS

Irq. J.

0Ti-Lrky^)lLCfj"7t

Ft^ 9.

Jbi

^^•7'

4,05.

Sot/et^' fiae^s^J

TrkjfLe Commfn^rJ /fT C/tp

?oz d^y disc^

Tz^.S, 7r

(pr'im.eif^j

^W.6.

^^ 7oz 7>rii

SFi^.S.

weiiera.GfiMtam.Lr!' urhoxenden.





CHAPTER XVI.—HASTY DEMOLITIOMS 85

t"he detonating compound (fulminate of mercury) ; above this

is a wooden plug with a hole in it, through which passes a

piece of quickmatch. The upper end of the tube is empty,

for the insertion of the fuze, and is closed by a small paper cap.

These detonators are packed in tin sealed cylinders painted

red, which contain 25. A new pattern No. 8, with a short

shank, will shortly be introduced.

No. 8 detonator will detonate dry guncotton, but it will not

detonate wet guncotton or cordite without a primer. Both

safety and instantaneous fuze can be connected to it.

Where dynamite is obtained a smaller kind of detonator Com-

used in civil works will often be available and should be used in mei-ciai

preference to No 8 detonators as being more economical.*^''^'^^^

This is the " commercial cap," which is made of copper, and

contains less fulminate than the No. 8 service detonator, see

Fig. 9, PI. 68.

These caps vary slightly in size and strength. To detonate-

dynamite, trebles are used as a rule. The weaker sorts cannot

be counted on to detonate guncotton primers, but "sextuples"

are strong enough.

They can be connected up to safety or instantaneous fuze.

Detonators must be stored apart from explosives ; when Storage-

attack is likely they should be protected from bullets.

Fuzes.

206. The present pattern of safety fuze is known as " Safety, Safety

No. 9." i"2s-

This consists of a train of fine gunpowder enclosed in jute

yarn, covered with guttapercha and waterproof tape. It

is packed in tin cylinders containing 8, 24, or 50 fathoms.

It is coloured black.

Safety fuze will burn under water. Bnmin^

underwater.



86 CHAPTER XVT.—HASTY DEMOLITIONS.

Bate of For practical work the rate of burning can be taken as 3 to

burning. 4 feet per minute.

Old fuze. Old fuze should have its rate of burning tested before

being used. Fuze which has been more than six months or so

in a tropical climate should be very carefully examined.

Lighting It is difficult to light safety fuze with a match or flame. Aportfire or vesu\'ian (fusee) is best, but in the absence of such

means of ignition,, the head of a match inserted in the fuze and

lit by another match, forms a good method of lighting. Aglowing cigar, cigarette or pipe is also good for the purpose.

Instantaneous Fuze.

Instanta- 207. Consists of two strands of quick match enclosed in flax

neous and several layers of guttapercha and waterproof tape,fuze.

j^ burns at the rate of 30 yards a second, or practically in-

stantaneously ; it is packed in sealed tins holding 100 yards.

It is coloured orange.

It can be distinguished in the dark from safety fuze by

feeUng the open crossed thread snaking outside it.

Joining Fuzes.

Joining 208. In firing charges with instantaneous fuze, a piece of

fuses. safety fuze should be joined on for hghting, in order to allow

time for getting away, except in special cases where the instan-

taneous fuze used is long enough to admit of being ht from

a safe place.

Joining To join safety and instantaneous fuze, cut the instantaneous

safety and f^ze on the slant so as to expose the quickmatch for a shortinstanta-

igng^ji Îso the safetv fuze in the same wav, takino; care thatDCOU.S O '• ^^ ? o

fuze. the composition is well laid open.

Join these two surfaces together and bind up tight. A small'^'

piece of wood is useful as a splint, and if handy, a little powder

or quickmatch can be put between the two fuzes (Fig. 2, PL 68).

Joining To join two lengths of instantaneous fuze, slit the outer

^^° covering of each piece of instantaneous fuze at the end, it

if"? t^^^ ^^^^ ^^ turned to expose the quickmatch

;the strands are

neous then twisted together, the outer covering made to overlap the

fuze. joint, and firmly fixed with twine.



enAFTER XVI. —HASTY DEMOLITIONS. 87

Joints in fuze can be made waterproof by wrapping them Water-

round tight with indiarubber tape smeared with indiarubber pf'ôfing

solution, which aro articles of K.E. equipment. Ordinary'^"^ ^'

tape and tallow would do for a short time against damp.

Simultaneous Charges.

209. Charges are best fired simultaneously by electricity. Simulta-

When this is not available, it may be done as shown in Fig. 3, ^^"^

PL 68, by using equal lengths of instantaneous fuze, " 6c,"'°

which are ignited at " 6 " by a length of safety fuze, "a?>."

The joint at " b " can be made with a small bag or box

of gunpowder, into which the end of the pieceof

safetyfuze

and the ends of the instantaneous fuze are led, the quick-

match in the latter being exposed.

Care must be taken that the lengths of instantaneous fuze

are equxil, irrespective of the distance from the powder box to the

charges.

Substitutes for Service Fuzes.

210. When service fuzes are not available, means of firmg

must be improvised.

" Mealed powder " (which is very fine), moistened, or ordinary Mealed

gunpowder ground into a fine paste with water between two powder,

pieces of wood, can be pressed into a tube and used instead

of safety fuze.

Tliis burns at the rate of 2 feet per minute, or slower, depend-

ing on the dampness of the powder.

Powder hose, made up by filling tubes of strong linen Powder

with fine powder, can be used instead of instantaneous fuze, ^ô^^-

The tubes can be from -J inch to 1 inch in diameter, madefrom one strip of stuff ; they are loaded in lengths up to 20 feet

through a funnel. The lengths can afterwards be joined.

It burns at the rate of from 10 feet to 20 feet per second.

Precautions.

211. For amount of explosive required, see Chapter XXI. General

For cordite and dynamite use slightly more than is required^^^^'

for guncotton.




Storage of

(letonators

iu cam}3.

Connect-

ing updetona-

tors.

Connect-

ing up

caps.

Protec-

tion to

detona-

tor for

lamping.

When possible, tamp all charges. If guncotton charges

are tamped, one-half the charges given in the table are sufficient.

For demohtions in the presence of the enemy, increase thecalculated charges by 50 per cent.

Detonators should be buried to prevent being exploded by

stray bullets.

When connecting up No. 8 detonators with fuze, the de-

tonating ends of the fuze should not be pointed at anybody.

When carried out under fire, take every precaution against

a possible failure ; detail spare men to carry the stores to

replace casualties, and see that every man with the party has

tl'^^ mean." of lighting the charge.

For large charges of all sorts which cannot easily be got at

after tamping, and for demolition work where certainty and

rapidity are essential, it is a good rule to insert two fuzes (and

detonators if required) in the charge in case one should prove^

faulty.

When pinching or bending the mouth of a detonator or cap

to grip the fuze, care should be taken not to squeeze the

detonating end.

When tamping a guncotton charge with earth, stones, &c.,,

the detonator should be protected from being knocked.

Make arrangements to prevent sparks from the fuze causing

premature explosion of gunpowder charges, or setting fire to

guncotton.

Brickwork and Masonry.

General. 212. For the demolition of brickwork or masonry with gun-

cotton, the charges worked out by the formulae in the table-

will sometimes be too small to allow the whole length of th&

breach to be cut, being covered with whole slabs touching each,

other. In such a case :

(a) If guncotton is available, do not divide slabs, but add

extra slabs till the whole length to be cut is covered

by slabs touching each other.

(6) If plenty of guncotton is not available, cut some of

the slabs so as to make the charge stretch right across.

Smaller pieces than thirds of slabs should not be

used.








213. Where there is a series of arches, as in a viaduct, the Brick anca

best result is got bv cutting the piers and so bringing down two masonry

arch

b rid "res.arches for each charge, but in hasty demolitions this can only

^

be done when the piers are thin and high.

214. The best explosive to use for this purpose is guncotton. High and

The charge should be placed w^here the section of the pier is thin piers,

smallest, and if possible a groove should be cut in the pier to G"""-

place the charge in ; this reduces "T" and also to some extentco*^*^<^^'

tamps the charge. Otherwise the charge should be tied in a

continuous strip along a board, and this fixed on to the pier with

the guncotton next it (PL 70, Fig. 1, and PL 69, Figs. 1 and 2).

215. The piers cannot be satisfactorily demolished withGun-

gunpowder in haste, as the speediest method of placmg the powder,

charge would take some time ; it would generally be better

to attack the arches.

The following is the quickest Avay of attacking piers :

Divide the whole charge into two or three parts, and as the

chambers cannot be cut in the pier, place the charges in pits

dug in the' ground close alongside each pier. Tamp with earth

and fire simultaneously. If the piers are in water the above

cannot be done.

216. The amount of guncotton and gunpowder for cutting Short and

short and thick piers is prohibitive, and the arches should be thick

attacked. The best method of doing this is to place a charge P^^''^-

at eacJi " haunch " of the arch. This ensures a much larger gap

being made than if only one charge were placed at the " crown."

217. If guncotton be used, a trench must be dug down to the G-un-

back of the arch ring at each haunch. Then the slabs (tied to cotton,

a board if possible) should be laid all along the trench on the

back of the arch ring. If it is desired to economise the

explosive, tamping maybe used, but it is not essential (PL 70,

Fig. 4).

218. If gunpowder be employed, the charge for each haunch Gun-

should be divided into equal parts, which should be placed powder,

about twice the thickness of the arch-ring apart from each

other, the outside ones being placed twice the thickness of the

arch-ring from the side walls, to avoid the charges blowing

out through the side walls. A pit must be dug for each

portion of the charge down to the back of the arch, and tamping

is necessary equal to twice the thickness of the arch.



unaer

arch.


In all cases the charges at both haunches should be fired

simultaneously.

When there is not enough time to reach the haunches,

the crown {a) may be attacked in a similar way, but the result

is not so satisfactory (PI. 70, Fig. 4).

6iin- 219. Where time presses, small arches can be cut by gun-

cotton cotton at the crown without digging through the roadwav. The

charge to cut through the arch can be tied in a continuous

strip along a plank, and this hold up underneath the arch

by ropes from the parapet at the qtovhi, vdXh. the guncotton

next the arch. These ropes should be windlassed up tight

so as to ensure contact between the guncotton and the arch.

The plank should be supported or trussed to prevent sagging

in the middle.

Walls. 220. To demolish a wall by guncotton, a groove should be

cut, if possible, for the charge in the wall ; if not possible,

Gun- the charge should be laid against the wall. {See PL 70,cotton.

pi^g_ 2 and 3.)

Gun- With gunpowder the total charge should be di\dded up into

powder. parts, each part being placed from the next a distance equal

to twice the thickness of the wall. Earth tamping shouldbe used.

To bring down the top of a wall, the length of the breach

cut must be not less than the height of the wall.

Houses 221. For weakly-built houses, place a charge in the centre of

and huts.^^^^ room, shutting all doors and windows. If possible, fire

charges simultaneously by electricity. The amount of

explosive required depends on the size of the rooms and the

nature of the walls. Mud huts up to 18 ft. square, with walls

2 feet thick at the bottom, have been destroyedby

about

4 lbs. of guncotton placed inside the hut in one corner, all

openings being closed; 6 to 12 lbs. of guncotton will probably

destroy a four-roomed cottage. For strongly-built buildings

it mav be necessary to attack the walls.

Towers of 222. Towers such as those in the North-West Frontier ofstone and

j^^^^^ ,^^^ usually 15 feet to 20 feet square in plan, with walls

3 feet or 4 feet thick, solid up to a height of 15 feet to 20 feet.

Gun-"Yi^Q walls consist of stone and mud. \^'ith layers of brushwood.

CO ton. rp^blow down one of these, a tunnel should be made into the

centre of the tower under a layer of brushwood (which keeps



PlctJbe 70.

HASTY DEMOUTIONS.

J-t^.7.

^P^-3.

J^^.^,

8. 05. WeilerA Graham, L»^ Li tho. London.

Opposifje pcuge 90.








Timber may be made to fall in any required direction hy

getting a strain on it beforehand with a rope.

Timber or 228. The most convenient way to place a guncotton charge

timber and against a stockade, so as to ensure contact between the slabs,

^f , , is to tie them beforehand on to a board, and to carry this up

with the guncotton attached; a hole must be cut in the board

for the detonator and fuze (PL 69, Figs. 1 and 2).

Gun- The board is placed with the guncotton next the stockade,cotton.

j^jjjj ^^yQ piciêts can be driven into the ground to keep it there,

or a couple of nails driven into the stockade, to which, the

charge may be hung.

The length of the board and the charge must equal the

breadth of the breech to be made.

Gun- 229. A gunpowder charge can be made up as follows (PI. G9,

powder.j'igg 3^ 4^ and 5) :—

Making up The powder should be placed in a well tarred sandbag, or

tlie charge, faihng that, in one sandbag inside a second one. About half

the powder is first poured into the bag, and then the safety

fuze, knotted round a stick to prevent its being pulled out, is

Connect- inserted, a piece of stout wire or a withe being also attached

ing up ^^ ^j^g stick, to help to support the fuze after it leaves the

means of mouth of the bag. The rest of the powder is then poured into

ignition, the bag. and the mouth is secured with spun yarn as shown, so

as to make it more easy to carry, a last seizing of the spun

yarn being made round the fuze so that any pull on it wiD

fall on the spun yarn and not on the fuze iteslf

The fuze will almost invariably ignite the charge by burning

through its wrapping as soon as it reaches the powder. The

necessary lengths of fuze should therefore be measured from

outside the mouth of the bag.Instantaneous fuze in addition to safety fuze should not be

used where there is only one charge, as it increases the liability

to missfire.

Placing 230. To place a bag against a gate or stockade, the precau-

tliechavgc. tions mentioned in Sec. 211 should be observed, and, in addition,,

the men carrying the tamping bags should be thoroughly

drilled as to how the charge and tamping is to be placed.

The man carrying the powder bag on his shoulder leads the

way, and placing the bag, fuze down-wind, and so that the fuzedoes not curl up against the charge, against the stockade^




prepares to light. The other men, each carrying a bag in the

same way, successively drop them so as to place them as shown

in Fig. 5, PI. 69. The fuze is then lighted, and all get away as

quickly as possible.

For a gap 5 feet to 6 feet wide, a charge of 60 lbs. to 80 lbs.,

roughly tamped with sandbags, as shown in Fig. 5, PI. 69, will

suffice.

231. The gate of a fort may be treated as a very strong Fort gate,

stockade. As the thickness cannot usually be known, a good

margin in the amount of the charge should be allowed.

For guncotton 50 lbs. will usually be enough, either placed Gun-

on the ground or hung to the gate on a nail carried for the cottou.

purpose and driven in.

For gunpowder a charge of 200 lbs., tamped with sandbags, Gun-

should suffice. powder.

Railways.

232. On railways, the easiest parts to attack in hasty demoli- Bridges,

tions are the bridges.

233. Masonry arch bridges should be attacked as described Masonry

already. bridges.

234. Iron and steel bridges can be destroyed with small ex- iron andpenditure of explosive. steel

The girders maij be destroyed by placing charges of gun- bridges,

powder or guncotton beneath the ends at the supports ;"but Gun-

by far the quickest may is to actually cut the girders them- cotton,

selves with guncotton.

Nearly all girders consist of a top and a bottom "flange

" or Girders.

" boom,'' cr^nnected by a " web,'' which may either consist

of continuous plating or of open cross bracing.

All girder bridges have at least two main girders which Usual

carry the flooring and go right across the span, and these main arrange-

girders alone need be attacked. "^^"'^ '^^

As a rule the best effect will be produced by cutting a girder bridges.

near a point of support, and this course will be economicalp^g-î^^ q£

of explosive, as the flanges are usually slighter at the ends than charge,

at the centre. In the case of a girder continuous over several

spans, the point selected should be in the first or last span, at

the end awav from the shore.



94 CHAPTER XVI —HASTY DEMOLITIONS.

If there is any doubt about the efiect of one charge, the girder

should be cut at each end of a span.

In the case of girders buiit on the archprincipal,

two chargesshould always be employed, with the object of blowing away

a segment of the arch. (PL 71, Fig. 5.) In girders with an

open web, the top and bottom flanges should be cut. In

girders with a plate web (unless this is very thin relatively to the

flanges) both flanges and web should be cut. When there is

a lack of explosive, the bottom flange is the most important to

cut.

Charge?. The arrangement of the charges will depend on the section

of the girder ; to simplify the firing arrangements, they should

be divided up as little as possible. The charge for the top

flange will generally be placed on the top, and that for the

bottom flange underneath. In each case they will be most

easily fixed if fastened to a board. The charge for the web,

if any, should be tied to a board, the ends of which can be wedged

up between the flanges.

Where there is a choice between masonry and iron girder

bridges, the girder bridge ought, as a rule, to be attacked, as

the demolition of the girder bridge will be much quicker,

and will save guncotton {see PI. 71).

RmIs. 235. Two-thirds of a lb. of guncotton is necessary to destroy

heavy rails. Two-thirds of a lb, is most conveniently got by

cutting a l|-lb. slab into thirds, as this size fits into the web

of the ordinary sized rail.

Six 2-oz. primers (with the detonator in one of them) will

also do, but is not so convenient to fix. Where the charge

can be wedged between the rails at points or a crossing, a

less charge will do this, as this tamps it.

On the straight line the slab should be tied tight into the

web of a rail close to a chair on the same side as the key.

Lead strips are provided for fixing the slabs to the rail, but

string suffices (PL 72, Figs, 2 and 3), or the key may be

removed and the charge put in its place. In the hasty

demolition of a railway fine care must be taken that the break

J6 sufficiently broad, or the rails displaced, so as to ensure the

stopping of traffic.

An effective way of damaging a railway line is by firing



I>lat^ IL

GIRDER BRIDGES

VrT\ I I I

Wedged

JôsztioTLr o/" CTiccnaes 21X,

ope

Clip

JfooderL

riifu

GirdLer' -itztA plate.

-^^.

•pT'znczpZe- sTvcnvrLhy ciott&d^

Fi^.^.

Ti^6

CTtaarffe-TrL

FToTLofytrdeT^

8 <tS.






charges under the rail joints. This will bulge the rails

vertically and make traffic impossible. This method however

requiresalarge

amountof explosive. If alternate joints are

attacked every rail mil be damaged.

236. Blowing in tunnels is a very good way of stopping traffic, Tunnels,

but to be effective requires a large quantity of explosive.

Gunpowder is best for this. Gun-

The points attacked should be some distance wîthin the powder.,

tunnels, and it is better to blow dowm one long tunnel in several

places than several tunnels in one place only.

The crown or the haunches should be attacked as in cuttingI

arches, and the lining should be brought dowm for some distance

along the length of the tunnel.

In hard soil it will not do much harm to cut the lining only,

as very little of the soil may fall.

The charges should be placed as far back from the interior Placing

surface of the arch as time and explosive available will allow, charges,

and twdce as far from each other as from the surface.^

For calculating the charge, T should be taken as the total Amount of

Jdistance from the surface of the lining to the charge. ^ arges. ig

The charges should be in chambers branching off the gallery ^^dug in from the surface of the tunnel.

Instructions for the Destruction of Guns.

237. (1.) A shell having been loaded in the ordinary wây, the Field and

guncotton charge necessary for the destruction of the gun î^gi? guns

should be packedin

behindit

so as to be in close contact wdththe shell and with the sides of the chamber. After the insertion

of the primer, sods, earth, paper or other material that may be

at hand should be used to keep the guncotton in position.

(2.) The breech block should then be swung to as far as

possible, just allowing room for the safety fuze or electric leads

for igniting the charge.

(3.) The charges required for guns from 3-inch to (3-inch

caUbre are given by the following rule :





PlaX^ 72

HASTY DEMOLITIONS

^ <^.

Fi^.S.

. OS.WellerAGrahaw.LW Litha Undort.





CHAPTER XVII.— HASTY DEMOLITIONS. 97

The water supply of a line should invariably be attacked, Water

and the more complete the destruction of tanks and pumps supply.

the better.

240. The rolHng stock, if it cannot be removed to the rear, Rolling

may be rendered unserviceable by burning; or trains may stock.

be run against each other at full speed on the same line, or

they may be run over an embankment by turning a rail.

Locomotives may be rendered useless, but still repairable,

by taking oft the inj ector, or the connecting rods on each side

of the engine, or the piston or safety valve.

In carriages the springs may be removed so as to let the

body of the carriage fall on the wheels and axles, or the axlesthemselves may be cut through by guncotton.

241. The method in which the permanent way is attacked Perma-

must depend greatly on the extent of damage desired, the time ^ênt way.

at disposal of the demohshing party, and the strength of that

party.

<:\ simple method, when explosives are not used, is to removeportions of the hue at intervals, especially at curves, removeswitches, &c., and carry them away. To remove the rails,

unscrewthe fish-plate nuts w-ith a spanner, if available, if not,

they may generally be broken ofi by hammering. The enemywill find considerable difficulty in fitting in rails of the right

length in the demohshed portions, but if this method is adopted

on a double hne, at least one line of rails must be entirely

removed, and the other partially so, otherwise an adversarv

might renounce the advantages of a double Hue for a time, andemploy the material from one line of way to complete the

partially destroyed one.

242. A second method, used wheremany men

are available,

and where the time is short, and the plant not required elsewhere,

is to attack the Une at several point at once, tear up the per-

manent way and render it useless on the spot.

Labourers are employed in preparing sleepers in piles for burn-

ing, placing rails upon them, and then twisting them. If the rails

are only bentthey can bebent back and used again, but if twisted

they must be sent to regular workshops to be re-rolled before

they can be utihsed. The chairs should be broken by a sledge

(5289) G





CHAPTER XVII.—HASTY DEMOLITIONS. 99

obtained for a short time by a raid ; since if any part of the line

lay in a part of a country from which the enemy had been

expelled it would be of course easy either to disconnect the.

wires and appropriate them, or, leaving the lines intact, to "3interpose instruments, and thereby read any messages sent by *

the enemy.

247. The poles can be readily cut or blown down, the easiest Destruc-

and safest poles to attack being those that have stays. tion of

A rope should first be fixed to the top of the pole or thrown ^^^'^^^ '^'^^•

over the wires in order to put on a strain tending to overthrow

the pole.

The pole shouldthen be partly cut through at about i feet

from the ground. All hands should then commence to strain

on the rope, except one man, w^ho should cut the stay through

with a file or pliers. The men on the rope must be sufficiently

far from the pole to be well clear of the wires when they fall.

The destructive effect will be increased by previously

cutting partly through the adjacent poles on each side, and,

if several adjacent poles are also stayed, cutting their stay at

the same time.

Cast iron poles can easily be broken with a sledge hammer.

Having brought down as much as possible of the line in this

way, the wires should be cut at each end as far as can be reached,

and twisted up so as to be rendered useless. The insulators

should also be broken.

Any damage of this sort, however, can be quickly repaired by

the enemy using cable, and even the complete restoration of

poles and wires w411 not take very long to accomplish.

248. Probably an equal amount of delay could be occasioned Faults,

with less trouble by skilfully placing what are known as

" faults " on the Une.

Faults consist of " disconnections," "leaks," and "contacts."

" Disconnections " are partial or complete breaks in the

continuity of the conductor.

" Leaks " are partial or complete connections of the conductor

to earth. A complete connection is known as " dead earth."

" Contacts" are formed by one wire touching another or being

put in connection with it by some conductor. They are very

troublesome faults, since they affect two Hues, and cannot be

(5289) G 2



100 CHAPTER XVII.—HASTY DEMOLITIONS.

Durcagedone to an

office.

Destruc-

tion of

subter-

ranean

line.

Destruc-

tion of

subaque-

ous line.

overcome, as other partial faults can be, by increasing the

battery power.

All artificial faults, however, to be successful as causes of

delay require to be skilfully made, and the description of the

methods of making them is too technical to be suitable for

inclusion in this book.

249. If possession can be obtained of an office, wires can be

discomiected. Any papers connected with the working of the

line and, if possible, the instruments, should be sent to the

officer in charge of the field telegraphs.

Records of messages should be sent at once to the Head-

quarters.250. A subterranean line is naturally more difficult to

discover than an aerial one ; for this reason among others they

are now extensively emploved in countries liable to invasion.

In England they are rarely met with except in large towns,

where overhead wires are dangerous.

The existence of such a line being known or suspected,

marks should be searched for at equal distances apart, indicating

the position of test boxes.

These marks are usually about 100 yards apart, and generallyconsist of blocks of wood or stone numbered in succession.

They would very probably, however, have been removed by

the enemy.

If not to be found where the line is known to exist, a cross-

trench should be dug at right angles to the probable direction

of the fine, about 2 feet deep, and in this way the pipes may be

discovered. These can then be dug up as far as possible, and

bent or otherwise destroyed if means are available, the wire

being pulled out and cut to pieces.

If possible the trench should be carefully filled in and all

traces removed.

251. A subaqueous line is rarely employed except for

crossing seas or big rivers, but in time of war they may be

laid along the course of the rivers to connect towns on their

banks, as was done at Paris in the Franco-German war.

To destroy such a line it should be grappled for with a

grapnel, and when caught as large a piece as possible cut

out of it ; the piece should then be cut into smaller pieces and

thrown into deep water.



PART II.

CHAPTER XVIII.—STRENaTH OF MATERIALS

AND BUOYANCY.

Cordage.

252. The word " rope " is now officially u?3d to denote steel Kopes and

or iron wire rope, while hemp and fibre ropes are termed cordage.

" cordage." Colloquially " rope " is still used to denote

both classes.

The size of a rope is denoted by its circumference in inches,

and its length is given in fathoms. (A fathom is 6 feet.) Cord-

age is usually issued in coils of 113 fathoms, and steel wire

ropes in coils of 100 fathoms.

253. The breaking strain of ordinarysound cordage is obtained Strength

Q2 of cordage.

with fair accuracy from the formula 17 tons, where C is the

circumference in inches.

For field purposes C- cwts. has been laid down as the safe

working load for all cordage, but this may be increased, for

good cordage in good condition, to a maximum of 2C- c^vts.

254. The strength of wire varies greatly : as a very rough Strength

rule it may be taken that the breaking weight in pounds of wire,

equals three times the weight per mile in pounds. This rule

holds good for iron and hard drawn copper wire, while steel

wire may be taken as about twice as strong as iron wire.

The breaking strain in tons of iron wire rope is about equal Strength

to the square of the circumference in inches. Steel wire rope of wire

rope.





CHAPTER XVIII.—STRENGTH OF MATERIALS, ETC. 103

259. A bridge that will carry infantry in fours crowded at a

check will carry any of the field guns and m.ost of the ordinary

wagons that accompany an army in the field.

260. A good rough formula for calculating the necessary sizes Formula

for road bearers and transoms is given below. The formula ^^^ êct-

includes a factor of U for live load, and gives a factor of ^^S^^^'*

safety of 3 ; it also allows for the weight of superstructure.

Unselected rectangular beams

W=:^^xK {A)

Where W = actual distributed weight in cwts. (superstructure

not to be included).

h = breadth of beam in inches.

d — depth of beam in inches.

L = length of span in feet.

K = a variable quantity for different timbers (see below).

261. Uuselected round spars Formula

Vr=^x^:xZ iB) i-T"'

The S3mibols being the same as for formula (.4), h and d

being- here equal, and round spars being- only about -5^0 as

strong- as square beams of^ the same depth.

262. For larch and cedar .. .. .. K=l Yaluea

„ Baltic fir K = l oiK.

„ American yellow pine . . . A^ = f„ beech and English oak . . . A" = -^

In the above formula, W is the distributed weighty such as

that of troops, on any span.

263. If it is wished to use these formulae for a concentrated Concen-

weight, such asa

gun,the

actualweight on the gun wheels

irated

must be multiplied by two to reduce it to the equivalent^°^^^-

distributed load, when it can be substituted for W. When,

as in the case of a transom, there are concentrated loads at Transoms,

more than four points along the span, it will be sufficient to

take the total as being distributed.

264. With several baulks under a roadway, the two outer Baulks,

ones can be assumed as taking only half as much of the weight

as the inner ones.



104 CHAPTER XVIII.—STRENGTH OF MATERIALS, ETC.

the outer baulks each bear ^

Arrange-

menrs of

baulks.

Formula

for can-

tilever

bridge.

total

(In calcu-

Thus, with five baulks

weight, the inner baulks each bear J total weight

lating, the greater weight must be worked to.)

Rectangular beams are stronger on edge than on the flat,

and should be always used on edge.

265. In calculating the strength of a tapering spar when

used as a baulk, d is to be taken at the centre of the spar.

Experiment has proved that such baulks, when supported

at both ends and overloaded, will break in the centre, and

not at the small end.

Knowing h, d and L, from formula (A) or (B) we can find

TT^, the safe distributed load, for these data. Knowing \]\

and choosing L, a convenient length, we can find b and d^

the necessary section of the beam.

266. A rough formula for strength of cantilevers is as

follows :

W = ^ --r- X K for square timbers.

W= the total live load which can be brought to bear

on the end of the cantilever in cwts.

L = the length of the cantilever in feet.

h = breadth 1 - • i

,i = depth I'^-n^lê^-

/C = a variable quantity according to the tree for

values, see Sec. 2G2.

Formula

J or round

spars.

Weiglit of

•water.

For round spars :

X K,

These formultB .cîve an allowânce for superstructure an(

factor of safety of 3.

267. Useful facts-

One cubic foot of water = GJ gallons;

One gallon weighs 10 lbs.

Buoyancy.

Buoyancy 268. In using closed vessels like casks for floating piers, the

of casks, gafe buoyancy for bridging purposes may be taken at y% the

actual buoyancy.



CHAPTER XVIII.—STRENGTH OF MATERIALS, ETC. 105

269. The buoyancy of closed vessels can be determined Closed

by the following methods : vessels.

(a) When the contents are known

Multiply the contents, in gallons, by 10, and take -^^ of

this, which will give safe buoyancy in pounds.

(6) For casks, when the contents are not known

A cfval buoA'ancy = oC^L — AV lbs.

Safe buoyancy =yV

{5C-L - W} lbs.

Where C is the circumference of the cask, in feet, halfway

between the bung and the extreme end ; L is the extreme

length, exclusive of projections along the curve, in feet;

W is the weight of the barrels in pounds.

Collins*

rule.

270. The following are the dimensions, weight and buoyancy Table of

of certain casks : casks.



106 CHAPTER XVIII.—STRENGTH OF MATERIALS, ETC.

Buoyancy 271. The buoyancy of a log can be obtained by multiplying^ ^^ ^^'

its cubic content by the difference between its weight per

cubic foot and that of a cubic foot of water, viz.,

62|lbs.

The actual flotation then of the log given below, if it were

pine, would be :

95 X (62J- 40)

or 95 X 22^"

= 2,137i lbs.

As, however, timber absorbs a great deal of water, only | of

the above can be safely relied upon.

This available buoyancy will then be

I X 2J37| = 1,781 lbs.

272. The contents in cubic feet of an unsquared log of timber

can be found by the following rule :

L

^ (D- + Dd + d-).

Where L = length of log- in feet,

D, d = diameter at ends.

Thus, if the log- is 3 feet and 2 feet in diameter at the endsand 20 feet Ion or

Bridges of

rafts of

timber.

the cubic contents =20

95 c.f.

Wêightof 273. The follow





J'late 73.



107

CHAPTER XIX.—BLOCKS AND TACKLES—USE OFSPARS.

274. Blocks are used for the purpose of changing the direction Blocks

of ropes or of gaining power. and

They are called single, double, treble, &c., according to the tac'des.

number of sheaves, which are of metal or hard wood, and

revolve on the pin, which should be kept well lubricated.

Snatch blocks, Fig. 1, PI. 73, are single blocks with an

opening in the shell and strap on one side, to admit a rope

without passing its end through.

The rope with which tackles are rove is called a fall. To

overhaul is to separate the blocks. To round in is to bring them

closer together. When brought together the blocks are said

to be chock.

275. A tackle is rove by two men, back to back, 6 feet apart ; KecTing.

the blocks should be on their sides between the men's feet,

hooks to their fronts, and the coil of rope to the right of theblock at which there are to be the greater number of returns.

Beginning with the lowest sheaf of this block, the end of the

fall which is to be the standing end is passed successively

through the sheaves from right to left and then made fast.

276. In using tackle great care must be taken to prevent the Pre.

tackle from twisting. The best method is to place a handspike cautions

between the returns, close to the movable block, with a rope ^^^^^

to each end, by means of which it can be steadied. New rope

must be uncoiled and stretched before using it as a"

fall."Crane chain, when used as a fall, should be thoroughly Crane

soaked in oil. cliain.

277. Various tackles are sho\sTi in PI. 73. The power Power.

necessary to raise a weightW is W -f- number of returns at the

movable block -f- about 10 per cent, per sheaf for friction.

278. The fall, in lifting heavy weights, can rarely be worked Machines,

by hand, but has to be " led " to either a capstan or winch,

by which power is gained and a steady pull ensured.



108 CHAPTER XIX.—BLOCKS AND TACKLES, ETC.

Carrying 279. In carrying spars, the party should be equally divided

spars. on either side of the spars, facing it, and sized from one end.

The spar should then be lifted, in two motions, on to the inner

shoulders, the party facing one way. In lowering a spar, the

party should slowly face inwârds, and lower the butt end

first to the ground, and afterwards the tip.

Derricks. 280. A derrick (Fig. G, PI. 48) is a single spar set up with

four guys, secured with clove hitches. A tackle is lashed to

the head, and the derrick can be used for raising and swinging

a wêight into any position within its reach, which is about

one-fifth of its height. The anchorages for the guys should beat a distance from the foot of the derrick equal to twice its

height. The foot should be let into a hole in the ground to

prevent its slipping.

In Fig. 6, PI. 74, a derrick is shown in the act of raising a

pair of sheers.

Fig. 8 show^s a swinging derrick.

Sheers. 281. Sheers (Fig. 4) require only two guys—a " fore " and" back " guy. They should be fastened to the legs above the

crutch by clove hitches, the back guy to the fore spar, and

vice versa, so that their action may tend to draw^ the spars

closer together and not strain the lashing. The minimum

distance of the anchorages should be double the height.

The upper block of the tackle is hooked to a sling of rope or

chain passed over the crutch. Sheers can, as a rule, be used

for heavier weights than derricks, but can only move them in a

vertical plane passing between the legs. The feet of sheers

must be secured or let into holes in the ground. The distance

apart of the legs should not be more than one-third the length

of the leg up to the crutch, and the sheers not to be heeled

over more than one-fifth of their height.

Sheer 282. The legs of the sheers are laid side by side on a skid, andlashing. j-ept 2 inches apart by a wedge. The lashing is commenced

with a clove hitch on one spar, carried six or more times

upwards round both spars without riding, then twô Trapping

turns, and finished off wîth two half hitches round the other

spar. (Figs. 1 and 2, PI. 74.)



I*lcOte '74

Fi^.L

USE OF SPARS

jtiq.Z. Fry. 3

STveei^s

ybte. . JBiflFiff. S. fyctf^pTiriff turnsar^ cT/oMed'so us to s?to\^

WellerAGratwm.LH Litho.LofxJon.





CHAPTER XX.—FRAME BRIDGES, ETC. 100

283. Gyns, Fig. 5, require no guys, and are good for a Gyns.

vertical lift, such as dismounting gans.

The three legs of the gyn are placed as shown in Fig. 3,

resting on a skid, and 2 inches apart. The lashing is com-

menced with a clove hitch on an outside spar, and carried

upwards over and under loosely and without riding six times.

Two frapping turns are taken in each interval, and the whole

finished off with two half hitches round one of the spars.

Iron chain is better than rope for these lashings, as it admits

of fewer turns, which allows the legs to be more easily opened.

284. In using tackles with sheers, gyns, or derricks, the Leading

running end of the fall should always be led through a " leading blocks,

block," lashed, as a rule, to one of the spars a few feet above the

ground ; a snatch block is most convenient for the purpose.

(Fig. 7, PI. 74.)

CHAPTEK XX. — CANTILEVER BRIDGES, FRAME

BRIDGES, FRAMED TRESTLES, SUSPENSION

BRIDGES, AND CASK PIERS.

285. Pis. 75 and 7G show various types of cantilever Cantilever

bridges as used in Northern India. bridges.

From the smallest to Ihe largest span the method of con-struction is practically identical. A site is chosen where a

large rock or rocks rise out of the stream or a pier is con-structed of dry stone work and wooden bindings. On the

top of tliese are laid a number of stout beams, ««, projecting

over the stream, with the projecting end somewhat higher

than the shore-ends. The number of beams, their length andamount of projection depend on the span. The shore-ends of

each row of cantilevers should be covered with planks or like

material. Stones are then packed round these ends, and thev/hole weighted down. It is also desirable to lash the topiayers to the bottom ones as shown in Figs. 5 and G.



no CHAPTER XX.—FRAME BRIDGES, ETC.

Frame

bridges.

Single-

lock

bridge.

Double-

lock

br.due.

Supposin^!^ that the central span is too lar.iê for available

timbers, then more rows of cantilevers are placed on the first

row aa, two more transoms tt are placed near the projecting"ends and the roadbearers rr are placed in position. There are

<ienerally more cantilevers in the bottom row than in the row

above and so on. Figs. 5 and G.

The step from top row of cantilevers to top of central road-

bearers can be avoided by lashing the top transom underneath

the ends of the top rov/ of cantilevers instead of placing- it on

the top, or an extra row of roadbearers may be added above

the top row of cantilevers. In the case of a long bridge a

few wire ties are a great improvement, as they stiffen the

bridge greatl3\ Fig. 7.

286. The following are simple types of frame bridges :

{a) Single Lock.—Supporting one central transom, and

sufficing for a span up to 30 feet.

(6) DouUe Lock.—Furnishing two transoms, span up to

45 feet.

They are not so generally useful as trestle bridges.

The span of a frame bridge is the horizontal distance

between the footings of the frames, and is independent of any

increase of span due to sloping banks or bays of trestles.

287. A single-lock bridge (Pi. 77) consists of two frames

locking together ; one frame must therefore be narrower than

the other.

288. A double-lock bridge (PI. 77) consists of two frames

held apart by distance pieces. The frames must therefore be

thesame

width.

The frames are nearly identical with two-leg-ged trestles

{Fig. 2. PL 50). but the slope of the legs is not so great, ^~-

generally suflricing, and the transom and ledger are lashed on

on opposite sides of the legs, transom on the shore side so as

to bear on the legs, ledger on the outer side so as not to

interfere with the footings. Before lowering the frames into

their places footings must be prepared, holdfasts driven, fore

and back guys attached to the top of each leg, and foot ropes

attached to tach leg below the ledger. The frames are then



JÛtte^ 75.

CANTILEVER BRIDGES

Jî^.7

JSZei/atioTh

Bc$. W«lt«riGreh«m.L'^ lifho Lonoon

To fcLcepa^B JfO.





'Pl^fte 76

To faWjnv plate 75









CHAPTER XX.—FRAME BRIDGES, ETC. Ill

lowered, and if a single-lock bridge, locked ; if a double-lock

bridge, held back by the guys a little higher than their

ultimate position. A single-lock bridg'e is then completed

with the usual roadway : for a double-lock bridge two ^distance pieces must be placed across the ends of the frame

transoms, as shown in the diagram and the road-bearing

transoms lashed across, as shown. The back gu^'s can now

be eased, and the bridge allowed to lock. The roadway is

completed as usual.

In order that the parts of frame bridges may fit together,

considerable accuracy is necessary in taking the measure-

ments and marking the positions for the lashings. To this

end a section of the gap and proposed bridge should bemarked out on the ground, allowing for camber. The spars

for the legs must now be laid on this section in the exact

positions they will occupy when in bridge, and marked to show

proper positions for lashing on ledgers and transoms.

289. The following approximate dimensions of timbers for Dimen-

single and double lock bridges are necessary for carrying ^1*^"^°^

infantry in fours crowded :—

Legs . 7 inches at tip.

Frame transoms, mean diameter . . 6 inches.Distance pieces

,, ,, .. 11 inches.

Other spars as for trestle bridges.

290. Plates 78, 79 and 80 show examples of heavy trestles Framed

made of timbers framed together and fastened by iron dogs,t^^^^^^^*

spikes, bolts ^ etc. They are specially useful for hasty railway

bridges (see also Chap. XXIII) and for road bridges where

heavy traffic is expected. Skilled labour is required for

their construction.

These trestles usually consist of groundsills, capsills, uprights,

struts, and diagonal braces and stringers connecting the trestles

in the line of the bridge.

The uprights should be as far as possible arranged under the

road-bearers, so as to support the weight directly. Whenthey can be got of sufficient length, it is best to make the trestles

in one tier only, however high the bridge, taking care of course

that they are properly braced both ways to prevent buckling

(PI. 78, Fig. 1 and PI. 79, Fig. 1).

When the material is not long enough, the trestles must be



112 CHAPTER XX.—FRAME BRIDGES, ETC.

Struts.

Bra(

Corbel.

Pasten-inss.

made in two or more tiers. In this case the upper tiers must

not be made too heavy, or they will be very difficult to hoist

into position. The groundsills of the lower tier must be strong

enough to support and distribute the weight of the uprights.

Where the soil is firm and can be levelled to an even bed, no

other foundation than the groundsill is necessary ; where the

soil is soft a low crib pier may be made to distribute the weight.

The adjoining capsill and groundsill, where one trestle rests

on another, need not be very strong. A 3-inch plank will suffice

for each, and may be spiked to the uprights. In this case

the uprights may be fixed in position with cleats, and dogged

to each other (PL 78, Fig. 2).

291. The inclination of the struts depend to some extent

on the height, width and length of the bridge. They are not

essential for wide bridges of no great height.

Struts for railway bridges must have a greater inclination

than for ordinary bridges to provide for wind pressure on the

side of the train tending to overturn the whole structure.

This is especially the case when the bridge is high and long.

292. For the arrangement of the diagonal bracing, see

Plates 78 and 79.

The ends of struts should not be notched into uprights unless

the latter have a considerable margin of strength and stiffness.

Uprights and struts should be notched into groundsills and

capsills when possible ; but when time presses and few car-

penters are available, a careful arrangement of dogs will suffice,

without notching.

293. PI. 78, Fig. 4, shows a corbel, an arrangement for giving

a wider bearing at the top of a trestle ; and Fig. 5 an alternative

method, which also helps to fix the capsill.

294. Dogs, spikes and bolts are the most useful fasteningsfor framed trestles. The position of each dog should always

be considered with a definite object of preventing a possible

distortion of the frame. They should be on both sides of the

trestle. Dogs should not be driven within 3 inches of the edge

of a timber, or within 4 inches of its end.

Spikes, when used in pairs, should be driven inchning

towards each other. They run 5 inches to 10 inches in

length.



J>laJbe78

Fig1

rRAMED TRESTLE

Squared Timber

f-^'SX-A

Tt^ 2

7\

Fi^ 3

Jlwrong position^

for dog.

Fj^,^ Fvg 6

^ .a ^n;^ a aComposite roadhearers

wittcplxviks fhreaJujiq Joint

Welleri Graham L!f Lirtw. London

C)j)posvte page J^-^





ricute 79

FRAMED TRESTLES

Sleepy j.,se'.^

Fistcp

5 coaxifv scTt

Tresile with. \'

ilsTv phite g-^^^

rastemn^s

t boU

Vf'drvri%oUs ''^gdrU'-ii'olts ''/a'^drift l>oUs

-^M ' m^

FICLTV

Trestle of Flouaks

CapsilL ^ J-ron stiiap.

Wel!er46raham.l'* Liffto, London.





PlcLte SO

FRAMED TRESTLE

Round Timbers

"''' "" ~" •*"

' •''T^rfiiTr-ff^r4r;7-;;iri7r

Fi(j. 2

ELe\'aJLiorv






295. When round timbers are used the groundsills and capsills Framedmust be adzed to give a square bearing surface for the trestles of

uprights.

I'pund

When there are two or more tiers, it will be best for the^^ ^^'

upper tiers not to have groundsills. The uprights may rest

directly on the capsills of the tier below {see PI. 80.

They should be wedged up after fixing; to keep the trestle

together while it is being raised, a light timber or board maybe spiked to the sides of the uprights near their feet.

296. Formula for Use in Suspension Bridges.Suspen-

sion

bridges.

Length of cable between piers = a +-

W cr

W=. uniform

dead load on

y cables per

un of

Tension in cable, Tq

Tension at piers, Tg

Pressure on piers = W a J

Height of frame d •= -\- h' (length of centre sling) + camber (1 in 30)

For a concentrated load, such as that brought by a traveller, without

Adroadway, safe load on the cable = — x working- strength of

cable.

(5289) u



lU CHAPTER XX.—FRAME BRIDGES, ETC.

297. The followinf;^ table will be found useful for calculating stresses

due to uuiform loads on suspension bridges; in it the load is \Vx a :

1-




table, showing" the holding power of dry loam at varioiuj

depths and inclinations of cable ;

Mean depth of Face of

Anchorage below

Surface.



116 CHAPTER XX.—FRAME BRIDGES, ETC.

Braces. Braces of IJ-inch rope, 3 fathoms long, a small eye splice

at one end, and a figure of 8 knot 1 foot 5 inches from the

eye.

Ways. The pier being made, is launched into the water by means of

a sledge called the ways.

Forming To make a pier the number of men required is two more thanpiers. double the number of casks, or 2 n + 2, where n is the number

of casks.

Four men stand at the ends of the gunnels, the remainder

opposite the intervals between the casks on either side. The

gunnels being in position, the gunnel men at one end place the

eyes of the slings over the gunnels ; the gunnel men at the other

end secure the slings to their ends of the gunnels with a round

turn and two half hitches. The brace men keep the slings

under the casks with their feet, and as soon as they are secured

adjust the braces as follows, the men working simultaneously

by word of command.

The eye of the brace is passed under the sling in the centre

of the interval between two casks, the end passed through the

eye and hauled taut, the sling being kept steady with the left

foot. The brace is then brought up outside the gunnel im-mediately over the eye, and a turn round the gunnel taken to

the left, the foot is removed from the sling, and each man then

hauls up the standing part of his brace with the left hand,

holding on to the turn with the right ; as soon as the brace

is taut the turn is held fast with the heel of the left hand, and

the remainder of the brace, in a coil, is placed on the cask

to the left. Each man then takes his opposite neighbours

brace from the cask on the right, and passes it between the

standing part of his brace and the cask on his left, then backbetween his brace and the cask on his right, keeping the bight

so formed below the figure of 8 knot on his own brace, and

placing the end on the cask to his right. Each man then takes

back his own brace from the cask on his left, passes it under

the gunnel to the left of the standing part, places his foot against

the gunnel, and hauls taut. The pier is then rocked backwards

and forwards, all the brace men taking in the slack of their

braces and hauling taut until the word steady is given^ when



CHAPTER XX.—FRAME BRIDGÊS, ETC. 117

they take a round turn round the gunnel to the left of the previous

turns, and make fast with two half-hitches round the two

parts of their own brace close to the gunnel, drawing the two

parts close together and placing the spare ends of their brace

between the casks. The pier is then turned up on one side,

and the sling adjusted below the third hoop of the casks, and

a breast line attached to the slings at each end : it is tlien lowered

and turned up on the other side, the other sling adjusted, the

vmys brought up into position^ and the pier lowered on to them

ready for launching.



118

CHAPTER XXI.—DEMOLITION FORMULA.

CHARaES FOR HASTY DEMOLITIONS.

Note.—The charge is in lbs. B = length to be demolished in feet.T = thickness to be demolished in feet.

i = thickness to be demolished in inches (in the

case of iron plate only).

In the presence of the enemy increase the charges bj 50 per cent.

GUNPOWDER (Tamped).

Object attacked.

Brick arch—one haunch

Brick arch—crown .

Brick wall

Wood stockade—hard wood

Stockadeof earth between

timber up to 3 ft. 6 in. thick

lbs.

Fort gate

Tunnels

fBT^

|BT2

|BT2

40 to 100

60 to 80 per

5 ft.

200

tT3

Remarks.

' Total amount divided into

charges placed apart about

twice the thickness of brick-

work.

One charge. Soft wood half

this.

One charge.

One charge.

Where T = total distance from

the surface of the lining to

the charge.



no

Note.

CHAPTER XXI.—DEMOLITION FORMULAE.

CHAEGES FOE HASTY DEMOLITIONS.

-The charge is in lbs. B = length to be demolished in feet.

T = thickness to be demollsbcd in feet.

t = thickness to be demolished in inches (in the

case of- iron plate only).

In the presence of the enemy increase the charges by 50 jêr cent.

aUNGOTrON (Untamped).



120 WORKING

Nature of Work. Dimensions. No. of lien.

1



PARTY TABLE. 121

Amount.

100 sq. yds. or 9 to

10 bundles of

60 lbs. each

About 300 bundles

of 50 lbs. each

2 paces

ICO

2 paces

100 sq. yds.

Tools.

Felling axes: hand axes;

saws, cross-c«t; saws,

band

I

Billhooks, lashing or wire;

Ia small portion of felling

) axes, hand axes and saws

a grindstone and a few

I whet stones

Billhooks and hand axes

1 measuring rod; 1 dicker;

3 billhooks: 2 knives ; 1

maul; 1 hand saw; 1 pair

of pliers

1 billhook; 1 mallet; 2

knives; 1 measuring

rod

2 billhooks; 2 knives; 1

mallet ; 1 pair of pliers (if

sewn with wire)

Sharpened

cutter

pades or sod

Crowbar or pick

3 billhooks; 1 maul ; 2 pairs

of pliers

20 yds. length. i 2 billhooks; 2 mauls; 2

pairs of pliers, 1 hand saw

Remarks.

For larger trees the diameter in inches cubedand divided by 144 will give the number of

ndnutes. With the hand axe allow 2 minutesper inch of diameter lor trees up to 1 foot;

for trees over 1 foot twice the calculated

amount.

Men opened at 4 yds. interval should cut

25 yds. to their front in 4 hours.

40 men cutting; 40 men sorting and binding;

20 men cartuig.

If very bushy a pole and ropes can be used

to expose their lower branches to the axe.

Materials : 4 bundles brushwood. 60 ft. of wire

or spun yarn if withes are not used. Weightabout 140 lbs.

One and a half bundles of brushwood. Weight

complete about 50 lbs.

10 bands, 10 pickets. Weight compl'ite, 13 lbs.

Trees used where felled.

1 sq. ft. of entanglement takes 1 ft. of wire.

sq. ft. takes 3 ft. of wire. Entanglement

built with 3 rows of pickets, each 2 yds. apart.

100 sup. ft.

wire and stakes for anchoring per 100 sup. ft.

allow ^ hour to 1 hour in addition to the calculated task.



122 CHAPTER XXII.—ROADS—BONING AND LEVELLING.

be

.£'Bo

5



123

CHAPTER XXII.—ROADS -BONING ANDLEVELLING.

Roads.

303. A roadway 10 feet wide (8 feet minimum) will take a width of

single line of wagons* passing in one direction, or infantry in roadway,

fours ; 12 feet is better as allowing horsemen to pass without

difficulty ; for each additional line of vehicles 10 feet should be

added to the width of the road.

Where there is little traffic, a width of 10 feet may suffice

for wagons both going and coming, provided sidings are made

at intervals, into which one wagon may go to allow another

to pass.

A width of 6 feet is sufficient for infantry in file or pack

animals moving in one direction.

304. The gradient for a short distance, such as a ramp leading Gradients.

on to a bridge, may be ^, or even J for infantry, i for artillery,

but for animals or wheeled traffic slopes steeper than :^\ areinconvenient, and if the incline be long it is still more desirable

to reduce them. Traction engines will, on good roads, draw a

load equal to their own weight up ^q, twice their own weight

up 2V5 ^^d three times their own weight on the level, or up

slopes not exceeding J3, which is the maximum gradient

in first-class roads.

305. Whenanew road has tobeconstructeditshouldbemade Laying

as straight as is consistent with the extreme gradient permissible, out a new

In laying it out the centre line should be marked by pickets,

^^^^'

spitlocking [i.e., marking out the fine with the point of a pick),

&c.

If the road passes through a wood, it will be well to cut down

a fine of trees in the required direction. The space occupied

* The ordinary -width of the wheel track of W.D, carriages is 5 feet

2 inches from out to out, except that of the pontoon wagons, which is

5 feet 10 inches.

The points of the axletree arms project about 6i inches beyond the

wheel track on each side.





PlccteSJ

METALLED ROADS.

î^,1.

K "5 --4«»i*-^ '-'^-T/ss- ^ o "- -

Fi^.Z.

^ r-3'*^'—}?^-^'^^' O' >j^-^;e>i

J^z^.S.

Weller 4 Graham.W LithaLonaon.

Opposite' poLg^ J24-.





Plat^SZ





CHAPTER XXII.—ROADS—BONING AND LEVELLING. 125

again as in the straight portions. Short zig-zags should he

avoided.

308. When a road passes over verv wet or marshy ground, and 'Roa^s

brushwood is available, it should be made up into fascines across

or hurdles, or even laid loose across the road (though this^^^^^nes.

plan is not so good as if made up) as foundation for the road

material.

309. When fascines are used there may be one, two, or more Fascine

layers (Fig. 3, PI. 82), according to the requirements of the ^ô^^-

case, the top row being always at right angles to the direction

of the road.

310. With hurdles their length should be equal to the width Hurdles,

of the road, and there should not be less than two layers across

the road, the layers breaking joint.

When the road is a permanent one it is considered ad-

visable to place the brushwood at such a depth below the surface

as will ensure it always being damp, as when it is alternately

wet and dry it soon rots.

Four inches to six inches of broken stone or gravel are then

laid on top, or, if these materials be not available, the earth

excavated from the trenches on either side is thrown there,

the surface being sloped as already described.

311. The trenches should be cut about 3 feet or 4 feet from Trenches,

the brushwood on either side, and outlets should be made from

them at intervals, to allow the water to discharge into lower

ground.

312. See Chapter XII. Corduroy

road«.

313. Eoads which are exposed to the traffic of heavy military Repair of

vehicles require constant repair. Parties of men under a^°^^^*

N.C.O. should therefore be told olf to every 3 or 4 miles of

road to keep it in order, and depots for road metaUing should

be formed at short intervals from which the material is dis-

tributed along the road as required. The material used maybe either broken stone (of a size to pass through a 1J-inch ring),

broken furnace slag, brick or gravel, which should be apphed

in thin layers, the surface of the road being first loosened

by scoring it with, the pick.

Tools.—Shovels, picks, rammers, measuring rods, levels, Tods.

&c. ; also, to break up the metalling, stone hammers 3 lbs.



126 CHAPTER XXII.—ROADS—BONING AND LEVELLING.

in weight, with handles 2J feet long, so as to work standing,

or of H lbs. weight, with handles 18 inches to 2 feet long, to

work sitting.

Boning and Levelling.

Levelling by means of Boning Rods.

Definition. 314. It is often necessary in the field to make a rough section

of a piece of ground or parapet, so as to calculate the amount

of work to be carried out, or to lay out short lengths of ground

at a given slope, as in road-making, drainage, &c. For such

purposes levelling by means of boning rods may be employed.Tools. 315. The tools required for boning are a field level (or a

mason's level, or a spirit level with a straightedge), a mallet,

pickets, measuring tape, a set of three boning rods, and where

great differences of level are met with, a long rod graduated to

read feet and inches.

Mason's The mason's level is sho\\Ti in Fig. 1, PI. 83, and can be made

level. by any ordinary carpenter, where a field level is not available.

Boninc Boning rods are usually made of deal, 3 inches wide and

rods. I inch thick, and consist each of a long arm, with a headdovetailed on at right angles to it (Fig. 2, PL 83). Care must

be taken that all of a set are of exactly the same length.

316. To make a section with such rods, it is usual to select the

highest point of the section and there drive in a picket flush with

the ground, driving in a second picket on the line of the section

with its top carefully levelled to the top of the first picket (by

means of the field, mason's, or spirit level), and as far away

from the first picket as the length of the level or straightedge

\\dll allow {see A, B, Fig.3, PL 83).

It is evident thenby

look-

ing over the tops of the two pickets (A, B), the depth below

the line of sight of any other points (C, D), on the section could

be determined by holding up a measuring rod at those points,

and the horizontal distance apart of the various points being

also measured, a rough section could be made. To avoid the

obvious difficulty of getting one's eye down to the top of the

first two pickets (A, B), boning rods are set up on them, and

a third boning rod (or the long rod) is set up at the different



:Plcxjtie< (S3

BONING & LEVELLING

-Z^.^.

^ s

JFigr.

-e —-i^ ;' TO —

i.l

'^MWa

-tjj ?jj

^^^/^

•ir

,Sj)irvbjLeyel

-^^MT:Fi^.5.

"%W;

H^kt, ang^fes to t^.ev^pTy)pej^ positiok

l.OS.Wcl!er& Graham. L<:'? Litho. London.

Oppos tte paê J2G.





M4xte^84.

Field Level

Fi^.l.

^-ji--i^;mr--iimi.

•cfciCd*^

Jz^.Z.





Plê-SS.

Field Level fcont^)

/CS tb CL/ ôot>.

Fi^.4^.

'^ Jê^êZy foZd^dîap

-%-^

JTasteirt^m^

We'erSGrdhani. w'" Lifho London

TcfolUnv plyjct^ 94.





m

/

*9Q€ if-ot.





CHAPTER XXII.—ROADS—BONING AND LEVELLING. 127

points (C, D, E) whose level is required to be known. The

boning rods being all of the same length, give by their tops

a horizontal line parallel to the first line of sight, but 3 feet

(or thereabouts) above It. In the same way a given slope

(say y^^) can be set out (i'ig. 4) by arranging the tops of the

first two pickets at the required slope (level A and B, 10 feet

apart, and then cut 1 foot off B), setting up two boning rods

on them, and by means of the third boning rod driving in

pickets to show the top of the slope at any required points,

N, 0, P. Again, a continuous slope between any two points

can be laid out with pickets, as in Fig. 5, by putting the firsfc

boning rod at F, the second at G, and with the third rod setting

up the intermediate pickets.

317. In taking a section it is usual to enter the levels, &c., Taking

in a book {see page 122). section.

Field Level.

318. The field level is shown in Plates 84, 85, and 86.

It can be used when closed

(1) As an ordinary spirit level for boning, levelling, &c.,

the spirit level being on the edge of the limb C.

(Fig. 1, PI. 84.)

When open

(2) As a square for setting ofE right angles. (Fig. 1.)

(3) As a protractor for setting off angles. (Fig. 2.)

(4) For setting off slopes of all grades, and as a mason's

level withplumb bob. (Fig. 1.)

In all cases place the limb A against the slope to be

measured.

The dotted Unes in Fig. 1 show how the instrument is

closed.

N.B.—One edge of the level is graduated in feet and inches.



128 CHAPTER XXIII.—RAILWAYS AND TELEGRAPHS.

CHAPTER XXIII.—RAILWAYS AND TELEGRAPHS.

Railways.

Forma-

tion.

Forma-

tion level.

Width of

railway.

Gauge.

319. The duties likely to be required of troops in the field

with re.^-ard to railways (apart from large railway schemes,

for which special arrangements would be necessary) may be

considered as either temporar}^ repairs, or the laying of short

lengths of line to join up breaks, the construction of addi-

tional works such as platforms, &c., to adapt the line for

military use, or the demolition of an existing line.

320. The formation includes the whole of the earthwork

necessary to complete the line to "formation level" and

secure the required width of way together with "side" and" catchwater " drains, and any " retaining walls" or protective

works to secure the bank against floods. Tuimels are included

under the head " Formation."

321. Formation level means the level of the completed surface

before the ballast is put on. On rapidly constructed military

lines, where ballast is possibly not available, the formation

level would be the depth of the rail and sleeper below therail level. The formation level is not absolutely horizontal

transversely, as it should slope slightly downwards from the

centre line towards the sides of the bank or cutting for

purposes of drainage.

322. The width of the railroad depends on the gauge, the

width of the rails, the clear space outside the rails and the

space necessary for drainage.'323. The gauge is the shortest distance between the inside

edges of the upper surfaces of the rails, and is | to 1 inch

greater than the distance between the flanges of a pair

of wheels.

In Great Britain, and most of the European countries, the

ordinary gauge is 4 feet 8Jinches ; in Ireland, it is 5 feet

3 inches ; in Russia, 5 feet ; in British India, 5 feet 6 inches

(metre, 3 feet 3| inches) and 2 feet 6 inches.

For a 4-feet 8j-inch gauge, single hne, the minimum width

of banks and of cuttings at formation level should not be less

than 12 feet and 16 feet respectively. These dimensions



CHAPTER XXIII.—RAILWAYS AND TELEGRAPHS. 129

might be taken for gauges of 3 feet 6 inches, or metre gauge

(3 feet 3| inches). For a 2-feet 6-inch gauge these miuimuni

dimensions might be reduced by 2 feet. For every additional

line of rail it is necessary to add the gauge plus two rail-

heads, plus a way between the tracks such that two vehicles

can clear each other witli their doors open and a little to

spare—say 11 feet for the 4-feet 8j-inch gauge.

324. General type of first-class English railwa}': Perma-

i?«/Z5.—Steel double- headed, weight 80 to 90 lbs. per '^^^^ way.

yard.

Sleepers.—Balric fir, 9 feet by 10 inches by 5 inches

(PI. 87, Fig. 2), weight 140 lbs. ; laid 3 feet apartcentre to centre, 2 feet 2 inches at rail joints.

Chairs,—Cast-iron ;width 6 inches or 8 inches ; weight

45 lbs. each ; secured by two steel spikes and twoscrews. (Fig\ 4.)

Keys,—Compressed oak, 6 inches long. (Fig. 4.)

Fishplates.—Steel ; weigJit 54 lbs. per pair ; secured

by four steel bolts | inch diameter. (Fig. 7.)

Ballast.

—Screened cinders, broken granite or slag,

size not exceeding 1^ inches cube, nor more than

10 per cent, to pass -^-inch mesh. Rounded gravel,

if used, to be mixed with sand or broken stone to

prevent it from working out from under sleepers.

In most foreign countries, however, the flatjooted or

Vignoles rail is used. This does not need chairs, and is

spiked direct to the sleepers, sometimes with a bearing-plate

between if the timber is of a soft description.

325. Two of the many different kinds of rails in use are shown EaiKon Plate 87, Figs. 5 and 6, the double-headed and the flat-

bottomed rails are usually made in lengths of from 15 to

30 feet, or even 60 feet, and weigh up to 110 lbs. per yard for

permanent lines intended for heavy traffic.

326. The rails are connected together by two fishplates of Rail

wrought iron or steel, each with four bolts with nuts and joints.

washers. The sleepers on each side of the joint are brought

closer together so as to reduce the bearing to about 2 feet.

(5289)I




Sleepers.

Ch lies.

Connec-

tion

between

chairs and

sleepers.

Connec-

tion of

rails with

chairs.

Connec-

tion

between

rails andsleepers.

Ballast

327. Sleepers are bearers, whether of wood or of steel, used

to distribute the weig-ht on the rails over the ballast or

roadway, aud in the case of cross-sleepers as a connection

between the two rails to preserve the g"auge.

Each mile of railway requires 1,850 to 2,000 sleepers.

328. Chairs are used to connect the rails to the sleepers,

when necessary owing- to the sectional form of the rail,

and to distribute the weig-ht over a greater bearing area

on the sleeper than is obtained by the rail resting on it.

329. Chairs are fastened down to sleepers by spikes and

treuails.

Trenails are wooden spikes, so compressed by machinery

as to expel all moisture from them. When they have beea

driven into the sleepers their tendency is to absorb moisture

and swell, and so to grip the sleeper more tightly. They

must not be employed alone, but where they are used there

should be at least one iron fastening to each chair, for,

although the trenail is a firm means of holding down the

chair to the sleeper, it is liable to rupture from a shearing

stress. For this reason, oak trenails with iron spikes driven

into them (PI. 87, Fig. 3) are often used.

In the case of flat-footed rails with good bearing area aud

exposed to moderate axle loads, the rails may be spiked directto the sleepers without chairs or bearing -plates.

330. The double-headed ;md also the bull-headed rail is

held in its chair by a key or small block of wood, compressed

b}' machinery (Fig, 4). This key is slightly wedge-shaped,

and is driven firmly into the gap in the chair at the side

of the rail. Rails may be ke3'ed on the outside or inside.

331. Flat-footed rails are generally connected directly with

the sleepers by dog-spikes, or with the interveutiou of

hearivg-plates.

332. Ballast is broken scone or other suitable material

placed on the formation level, on which the sleepers rest,

and with which they are " packed " to the proper level

or inclination.

The objects of ballast are:

i. To distribute the pressure imparted to it by the

sleepers over a larger area.



PZoJUSl

RAILWAYS

>Y7. Sr—Z^. O^.

FzQ.3

Flge.

13^' -

ried^

J^.7

^S^

Weller I. Graham. U?' Utfco. London.





P7<jcte6S.

RAILWAYS

Fi^ 1 Points of ^witches

nnnnnnn uuu a

Fi^.Z Cross over Road

Fi^.3. Crossing

y/vn^

.^^^^^^L

S. PSWtUer& Graham. L'f Umo.London








Material

depots.

Wagontransport

at rail-

head.

Labour. 336. Pôr railway work of any magnitude Jarg-e gangs of

unskilled labour are required, and this is especially true of

temporary re[)airs to be executed rapidly.

The proportion of unskilled to skilled labour -on temporary

repairs is as 7 to 1 ; on semi-permanent and permanent

repairs as 3 to 1.

337. An advance depot for railway material and stores must

invariably be formed at some place within 50 miles of tha

starting prjnt for repairs, and that before work begins.

338. [Sufficient wagon transport to carry 60 tons should, it

possible, be available at railhead to allow an advanced party to

move on, repairing minor breaks. Much time is thus saved.

Night 339. Provided that the arrangements for lighting works at

work. night are good, an equal amount of work can be done by day

and night shifts, and when repairs are being pressed, day and

night shifts are essential. The only class of work which

cannot well be carried on by night is platelaying, which

requires plenty of light along the track.

Flares, oil, or acetylene, are easily manipulated and give

good light for working parties.

Tern- 350. Up to 18 feet height. Crib piers of sleepers makeporary satisfactory bridges, which are rapidly built, as a large numberbridges.

qJ jj^^jj Q^n be employed to handle materials.

Between 18 and 25 feet, the speed at which such bridges can

be built decreases rapidly, not only on account of the additional

height, but because more material is used.

Water 341. Damages to water supply by the eneniy is apt to cause

fc^pply- much difficulty. Troops must not use railway water supplies

without special authority. A steam pump and boiler cariied.

on a truck is a useful adjunct. Lift and force pumps worked by

manual power, each with several lengths of hose, should also-

be carried. Engines can then make shift with temporary

watering ariangements.Tern- 3^2. To provide for entraining or detraining animals,,

poraryvehicles and sruns, extra siding and platform accommodation

^will become necessary at various points.

The sidings would be in extension of existing sidings, or

branch f i om the main line, according to circumstances.

The p/at/orms would, as a rule, be most conveniently placed

alongside a siding of sufficient length to allow of the train



CHAPTER XXIir.—RAILWAYS AND TELEGRAPHS. 133

being shifted so as to bring- different vehicles alongside in

succession.

Almost any available material may be used, but perhaps themost rapid method of construction is to make a crib work of

-sleepers (or similar baulks) and rails, or of sleepers only,

decked with sleepers, or planking of sufficient thickness to

carry the anticipated loads.

The edge of the platform must be just sufficiently far from

the rails to allow trucks and carriages to pass, and the top

should be level with the truck floor. No over-hang need be

îven. The decking should usually be held down by ribands

along the edges.

One or more inclined ramps will be needed at the back orends, according to length.

Telegraphs.

(The term Telegraphs includes also Telephones.)

343. Special troops are usually employed in the construction Line,

of telegraph lines, but it is as well that all should have a shght

knowledge of the principles of construction, if only with a viewto producing the greatest possible damage to the lines when

demohshing them.

344. For the transmission of messages by electric telegraph it

is necessary to have a continuous insulated conductor connecting

the various stations in communication.

345. By a conductor is here meant a metallic substance for Con-

conve\ang the current. For this purpose galvanised iron, ductor.

copper, or bronze wire is generally used, either as a single wire

or a smaller number of wires twisted into a strand, as in a rope.346. By "continuous" is meant that the conductor must Con-

not have the smallest break in its metalhc continuiy. The tiauous.

wire is necessarily suppHed in coils of convenient weight, as it

would be too heavy to manipulate if in one length. In the

joints however, metalhc continuity is ensured by soldering.

347. By " insulated " is meant that the bare conductor Insulated,

must not be allowed to touch the earth, or any neighbouring

^vires, or any substance of a conducting nature which may be in




connection with the earth or other wires. This is effected

usually either by " aerial Hues " or by " cables."

Aerial 348. An aerial hne consists of a wire suspended on insulators

of porcelain or glass, supported on poles placed at about

60-yard or 80-yard intervals. The poles should be of such

height as will keep the wire clear of obstacles and traffic,

and safe from malicious damage. No wire should be less than

12 feet from the ground.

Insulators. 349. The insulators are shaped like inverted cups having one

or more grooves round them. Porcelain insulators are usually

fixed to the pole or arm by means of iron bolts, the cups being

provided with an internal screw thread to fit the top of the

bolt (PI. 89, Fig. 2).

Wiring. 350. In erecting the line the wire is first stretched con-

veniently tight over several poles. It is then placed in one of

the grooves of the insulators and " bound in " securely with

a piece of smaller wire or tape binder ; thus at ordinary

insulators there is no break in the continuity of the wire.

Wires for telegraph circuits are invariably run straight^

that is to say, their insulators occupy similar positions on each

pole. On the other hand, important telephone circuits require

two wires, each of which revolves or twists round the other,

though of course they are kept well apart.

Poles. 351. The poles may be of iron or wood, usuallv the latter.

They should be buried in the ground to one-fifth their length,

and their tops protected by a piece of galvanised sheet iron

termed a " pole roof."

Arms. 352. ^Vhere more than one wire is carried on the same line of

poles, the ^vires are attached to insulators fixed on wooden or

iron arms, let into the pole, and at right angles to it (PL 89,

Fig. 1). The length of the arm depends on the number of

wires to be carried. When more than one arm is required they

are usually placed at vertical intervals of 1 foot.

Earth 353. Wooden poles, except m dry rocky ground, should be

wires. provided with earth wires, consisting of a piece of iron wire

running down the pole, under the head of each arm-bolt to the

butt, where it is stapled in the fo^m of a small spiral ; this

ensures the earth ^vire being well under ground. Each of the

arms is wired, and a turn of the wire is taken round the arm



JPâe^^ 89.

TELEGRAPHS

"ar^thyxnjê^

r1.

^- 3.

J'oZe/ ^r-ctchets.

We(fer&Gr3h»ni.L«! Litito. London.

To fcLce^pa^0 134





CHAPTER XXIII.—RAILWAYS AND TELEGRAPHS. 135

between each pair of insulators. This wire is also brought

under the nut of the bolt which secures the arm to the pole.

Earth wires serve a dual purpose ; they protect ths polesagainst lightning, and prevent the current from a faulty wire

leaking to other circuits, the current being conveyed by the

earth wire direct to earth.

354. "\Miere, from the pull of the wires, wi :d pressure, and stavs and

other causes, the poles are likely to be forced out of the vertical, stmts,

they should be stayed. Sta3^s are formed of stranded iron

wire firmly anchored in the ground and attached to the pole

about 2 feet from the top. When the pole carries a great

number of wires a second stay may be required, in which case

it is added below the first.

In situations where it may not be convenient to fix a stay,

a strut can be erected in a similar position, but on the other

side of the pole. Struts are usually about two-thirds the

diameter of the poles they support.

355. Insulators are sometimes fixed on anglt hrackets Brackets,

attached to chimneys, or ivatt brackets driven into the

masonry. Where arms are not used, pjle brackets (Fig. 3)

mav be employed to S'jpport the insulators.

Brackets are not usually earth wired.

356. The insulation of a conductor may also be effected by Cables,

surrounding it throughout its length with indiarubber, gutta-

percha, or other non-conducting substance. When this

insulating material is protected from injury by a coatincr of

plaited hemp, tape, or wire, it forms what is known as a cable.

A cable may contain one or more insulated conductors.

Cables are employed for :

(a) Under water lines,

(6) Under ground line 3.

(c) Lines on the surface of the ground.

357. When a cable is to be laid in the water it should be Cnder

strongly protected with a sheathing of steel wires, otherwise^"'^<^"-

the conductor is hable to be damaged by the anchors of

vessels, or by the motion of the water.

358. A similar kind of cable may be employed for under Under

ground lines, but it is generally more economical to lay a linegJ''3»^°<^-

of iron pipes into which the unprotected insulated conductors



136 CHAPTER XXIII.—EAILWAYS AND TELEGRAPHS.

can be drawn in convenient lengths. Joint boxes should be pro-

vided in the line of pipes at about 100 yards intervals to enable

the lengths of vrires to be connected. After the joints are

made they are covered over with indiarubber tape or gutta-

percha to insulate them. The position of these imder ground

boxes are marked so as to render them accessible when desired

for testing the wires or other purposes.

On the 359. For very rapidly establishing telegraphic communica-

surface tion in the field, a light single core cable u often employed. This*^^^^^, consists of a stranded steel conductor, moderately insulated

^ ' with indiarubber, and covered with plaited hemp ; thus

considerable tensile strength is obtained with a minimum

weight. The cable is laid out on the surface of the ground

temporarily ; if the communication is required for any length

of time an aerial line is constructed^ and then the cable i?

removed.



Sectiu)), I:es

136a

Date, 30th May, 1904.

No



';//"», nUNN STKKI DETAIL OF WORKING PARTIES. Datk, SOlh Mat/, 1004,

CIcartDff and

Trenclilll' ...

Bredhobst Hdr

dlRging trench (iBt relief)

clcarinR hedges in Iron

anddidgingiodsin

bloHinK up lliree isi

demolitiom(encl. win

^1= SI .-isis .

BEMAEKS.

1 for all trenches and redoubt. Kect i

a';

TraverserB revelttd:^ ft.al.»ith I E

Iirevelttd ott,-- 9 —^^-^j-

--7. V V

'

Section CommuniLalionTrench.

I

Ifa'nlfy om- f

1 ployed.

J



137

GLOSSARY OF TERMS.

Ihatis.—An obstacle formed of trees or branches of trees.

picketed to the ground, with their points towards the

enemy.

Banquette.—A bank upon which men stand to fire over a

parapet.

Berm.—A small space left between the parapet and excavations

of a work.

Bivouac.—An encampment without tents or huts.

Boinh-proof.—A shelter, proof against the penetration of shells.*

Calibre.—The diameter of the bore of a gun.

Cajoonier.—A small chamber formed in the ditch of a work

projecting from the escarp to give fire down the ditch.

Casemate.—A shell-proof chamber constructed for the accom-

modation of the garrison of a work or position.

Chess.—A plank forming a portion of the flooring of a bridge.

Command.—The vertical height of the crest of a work above

the natural surface of the ground.

Counterscarp.—The slope of the ditch of a work furthest from

the parapet.

Crest.—The intersection of the interior and superior slopes

of a parapet.

Crib-pier.—A support for a bridge formed of layers of baulks

of wood laid alternately at right angles to each other.

Dead ground.—Ground which cannot be covered by the

defenders' fire.

Defilade.—The adjustment of the levels of the crest and interior

portions of a work with a view to obtain cover for the

defenders or to screen them from view.

Derrick.—A single spar held up by four guys, used for lifting

or moving weights.

Embrasure.—A channel through the parapet of a work through

which a gun is fired.



128 GLOSSARY.

Enfilade fire.- -Fire which sweeps a line of troops or defences

from a flank.

Epaulment.—A small parapet to give cover to a gun anddetachment in action.

Escarp.—The slope of a ditch nearest the parapet.

Exterior slope.—The outside slope of a parapet extending

downwaj-ds from the superior slope.

Fascine.—A long bundle of brushwood, tied up tightly, used

for revetting, &c.

Fleche.—A work consisting of two faces, forming a salient

angle towards the enemy.

Fougasse.—A small mine filled with stones w^hich are projectedtowards the enemy on the mine being fired. "

Fraise.—A palisade fixed horizontally in a slope.

Gabion.—An open cylinder of brushwood, sheet iron, &c., used

for revetting.

Glacis.—The ground round a work outside the ditch. This is

sometimes made up artificially.

Gorge.—The face of a work furthest from the enemy.

Guy.—A rope fastened to the tip of a spar or frame, to support,

raise or lower it.

Gyn.—A tripod constructed vath three spars, used for raising

weights.

Interior slope.—The inside slope of a parapet (seen in section),

extending from the crest to the banquette.

Keep or Re'duit.—A separate enclosure within another work to

enable the defenders to resist after the outer line of defence

has been carried.

Lunette.—A work consisting of four faces, the two centre ones

forming an obtuse salient, the two side ones affording fire

to the flanks.

Lunette, hlunted.—A work consisting of five faces (otherwise

similar to a lunette).

Machicoulis gallery.—A balcony with a musket-proof parapet

in front, loopholed in the floor, to afford fire in a downward

direction.

Parados.—A traverse to give cover from reverse fire.

Profile.—The section of a parapet at right angles to the crest.

Redan.—A work consisting of two faces, forming a sahent angle

towards the enemy.



GLOSSARY. 139

Tledan, hlmited.—A work consisting of three faces, the centre

one firing to the front, the others to the flanks.

Redoubt.—A field work entirely enclosed by a defensibleparapet.

Relief.—The length of time that men have to work before

being relieved.

Revetment.—Any method of making earth stand at a steeper

slope than the natural slope.

Reverse fire.—¥iie directed on the backs of a line of defenders.

Riband.—A baulk fastened down on each side of a roadway to

keep the chesses in place.

Sap.—A trench formed by constantly extending the end.Sheers.—Two spars lashed together at the tip and raised to rest

on their butts, which are separated. They are used to lift

and move weights in one plane.

Splinter-'proof.—A shelter, proof against splinters of shell.

Superior slope.—The top of a parapet (seen in section).

Tackle.—Any system of blocks and ropes by which power is

gained at the expense of time {i.e., more power—less

speed).

Tambour.

—Aprojecting chamber or stockaded enclosure, con-

structed so as to flank the walls of a building.

Terreplein.—The surface of the ground inside a work.

Trace.—The outline of a work in plan.

Traverse.—A bank of earth erected to give cover against

enfilade fire, and to localise the bursts of shells.

Wattle.—Continuous brushwood hurdle work.



140





142



rNDEX. 143'



144 INDEX.



MILITARY BOOKS, published by Autkority—contmwfiA.

IiA.W. MILITARY. Manual of. 1899. Price 25.

MEDICAL SERVICES. ARMY. Regulations for. 1900. Price 9(Z.

MEDICAL SERVICES. ARMY. Advisory Beard for. Treatmcut of

Venereal Diseases and Scabies. First Report. Price Is. 6rf. Second Eeport. 1905.

Price 2s.

MEDICAL CORPS. ARMY. Manual. 1904. Price 'dd.

,,EXTRACT FROM. Sec. II. DrUls and Exercises. 1903.

Price :id.

REO-NS. FOR ADMISSION TO. May, 1902. Price Ic/,

MEDICAL CORPS AND aUEEN ALEXANDRA'S IMPERIALMILITARY NUESING SEETICE. Standing Orders. 1903. Price l.*;.

MEKOMETER. Handbook. 1904. Price 6c?.

POSITION-FINDER. Handbook. 1904. VviceSd.

RANGE-FINDER. Depression. Land Service. 1904. Price 4f?.

RANGE-FINDING. Field. With Watkin's Field Eange-fiuder and Tele-

meter. Handbook. 1903. Price 6d.

BASHFORTH CHRONOGRAPH. Report on Experiments with.

(1870.) Price Is.

SADDLES AND COLLARS, SORE BACKS AND SORESHOULDEES. A Manual of. By Veterinary Major Fred. Smith, Army Veterinary

Department. Third Edition. 1897. Price is.

SCOUTS. Training- and Use of. Price 2c?.

SETVAGE. Practical Treatment of. Price 6c/.

SIGNALLING REGULATIONS. 1904. Price 9c?.

DO. Extract from. Semaphore Signalling. Price Ic?.

SMALL ARMS. Text Book. 1904. Price 2.s. 6c/.

TELEGRAPHS IN WAR. Regulations for Working-, Price Id.

TELEGRAPHY. Army. Manual of Instruction in Field Telegraphs.

Price 3s.

TELESCOPIC SIGHTS. Land Service. Handbook. 1904. Price Ad.

TRACTOR TRIALS AT ALDERSHOT, 1903. Report on. Price 6d.

TRANSPORT MANUAL. (Field Service.) Part I. 1905. (Provisional.)Price 4d.

ROYAL MILITARY ACADEMY. ADMISSION TO. Regns.respecting. 1904. Price Id.

ROYAL MILITARY COLLEGE. Ditto. Price Id.

ROYAL MILITARY COLLEGE. Syllabus of the Course of Instruc-

tion at. 1900. Price 3c?.

STAFF COLLEGE. Regulations respecting the. 1905. Price 2c/.

TERRITORIAL REGIMENTS OF THE BRITISH ARMY. Nos.

1 to 67. Short Histories of. Price Id. each, or the whole bound in one volume,

price 5s.

VETEilNABY DEPARTMENT. Admission to. Regns. 1905.

Price Id.

MILITARY EXAMINATION PAPERS, viz. :—Entrance. Nov.-Dec, 1904. Price Is.

E.M. Academy (Fourth Class) and E.M. College (Fourth Division). Dec, 1904.

Price Is.

Staff College. Admission. August, 1904. Price Is.

Militia and Imperial Yeomanry. Competitive and Qualifying. March, 1905.

Price Is.

Foreign Languages. Modern. Officers of the Army. Oct., 1903. Price Is.

Eegular Forces, Militia, Yeoraamy, and Volunteers. Nov., 1904. Price Is.

SCHOOLS. ARMY:—Eegulations. Iv03. Price 4(Z.

Inspectors of, &c., &e. Standing Orders for. 1900. Price 4d.

Singing in. Eegns. for Teaching. 1901. Price Ic?.

Technical Terms and Words of Frequent Occurrence in Army Orders. Lists of.

1904. Price 2d.Type Exercises from Eegimental Orders for use of Candidates for 3rd Class certifi-

cates. Price '3d.



3

AFRICA, BRITISH EAST PROTECTORATE, AND ZANZIBAR.Precis of Information concerning. 1900. Price 3s.

CYPRUS. CompUed Toy Captain A. R. Saville, IStli Foot. 1878.

Price 2s. 6rf.

DUTCH ARMY (HOME AND COLONIAL). Handbook of the.

1896. Price 9d.

FRANCO-GERMAN WAR, 1870-71. Authorised Translation fromthe German Official Account, by Major F. C. H. Clarke, C.M.G., K.A.

First Vx-rt.—History of the War to the Downfall of the Empire.

Vol. I.—Sects. 1 to 6. Prom the Outbreak of Hostilities to the Battle of

Gravelotte. With case of Maps and Plans. Price 26s, {Out of print.)

Vol. II.—Sects. 6 to 9. From the Battle of Gravelotte to the Downfall of the

Empire. With case of Maps and Plans. Price 22s. (Out of print.)

Second Part.—History of the War against the Bepvblic.

Vol. I.—Sects. 10 to 1.3. From the Investment of Paris to the re-occupation of

Orleans by the Germans. With case of Maps and Plans. Price 26s.

Vol. II.—Sects. 14 to 18. Events in Northern France from the end of November.In the North-Avest from the beginning of December. And the Siege of

Paris from the commencement of December to the Armistice, TheOperations in the South-east from the Middle of November to the Middle

of January. (1883.) Price 26s,

Vol. III.—Sects. 19 and 20.* Events in South-east France from the Middle of

.January to the Termination of Hostilities. Rearward Communications.The Armistice. Homeward March and Occupation. Keirospect. 1884.

Price 31s. 6(Z.

Analytical Index. By Colonel Loksdale Hat.k. Price 1«. &d.

Section Also separately in paper covers.

1.—The Events in July. Price 3s.

2.—Events to the Eve of the Battles of Worth and Spicheren. Price 3s.

3.—The Battles of Worth and Spicheren, 1882, Price 5s,

4,—Advance of the Third Army to the Moselle, &c. Second Edition, Eevised andcorrected. With 1 Plan and 7 Sketches. Price 4s.

5.—Operations near Metz on 15th, 16th, and 17th August. Battle of Vionville

Mars-la-Tour. Price 6s. 6ci.

6.—The Battle of Gravelotte—St. Privat. Price 5s. {Out of print.)

7.— Advance against the Army of Chalons. Price 6s.

8.—The Battle of Sedan. Price 3s. (Out of print.)

9.—Proceedings on German Coast and before Fortresses in Alsace and Lorraine.

General Review of War up to commencement of September. Price 4s. 6d.

10.—Investment of Paris. Capture of Toul and Strassburg. Price 6s.

11.—Events before Paris and at other Points. Price 5s. 3i/.

12.—J.ast Engagements with French Army of Rhine. 1878. Price 4s. 6rf.

13.—Uccurrences on the Theatre of War in Central France up to the re-occupation

of Orleans by the Germans. (1880.) Price 6s.

14.—Measures for the Investment of Paris. Price 4s.



WORKS prepared by the GeneroJ. 67a^—continued

FRANCO-aERMAN WAR, 1S70-11—continued.Section

15.—Measures for Protecting Investment of Paris. (1880.) Price 2s 6i16.—Proceedings of the Second Army. Price 3s. 6rf.

17.—Proceedings of the First Army. Price 3s.18.—Occurrences on the South-eastern Theatre of War up to the Middle of January

18/1. Price 8s.'

19.—Occurrences on the South-east Theatre of War. Price 1.3s. Crf.

20.—General Retrospect of the War. The Eesults of the War. Price 5s

Handbook. 1901. Price Is.

Regms. 1900. Price 6(f.

Handbook. Second Edition.

By Major J. H. V.

FRENCH ARMY.GERMAN ARMY. FIELD SERVICE.GERMAN ARMY (Home and Colonial).

Price Is, M.

GERMAN FIELD ARTILLERY. Drill Regns.Crowe, B.A., Staff Captain. Price Is. 6d.

GERMANY: Campaign of 1868 in. Compiled by tlie Departmentof Military

History of the Prussian Staff. Price £1 Is.HOSTILITIES WITHOUT DECLARATION OF WAR. ByBt Lieut -

Colonel J. F. Maurice. E.M. 1883. Price 2s.

NILE AND COUNTRY BETWEEN DONGOLA, SUAKINKASSALA AND OMDURMAN. Report on the. 1898. Price 4s. \hd.

*

RECONNAISSANCE IN LITTLE KNOWN COUNTRIES. Hintson. By Captain C. E. Callwell, E.A., Staff Captain. Price Id.

RHODESIA, SOUTHERN. Precis of Information concerning. BvMajor C. T. Dawkiks, C.M.G. Jan., 1899. Price 2s.

STAFF DUTIES IN THE FIELD. 1891. Price 3«.

SUDAN ALMANAC. 1905. Price Is.

A

SUDAN CAMPAIGN. History of. In Two Parts, with case of Maps.By Colonel H. E. Colville, C.B., Grenadier Guards. 1390. Price 15s.

SUDAN. Handbook of the. Parti. Geographical. Part IT. HistoricalBy Captain Count Gleichen, Grenadier Guards, D.A.A.G. 1898. Price 2s,

DITTO. SUPPLEMENT. July, 1899. Price 2s. 6c/.

SUDAN, RED SEA, AND EQUATOR. REPORT ON THEEGYPTIAN PROVINCES OF THE. Ju y. 1884. Price 3s. eic/.

®^5Z.?J5 (GOVERNMENT) OF THE PRINCIPAL COUNTRIES.NOTES ON. 1882. Price 6s

DITTO. SUPPLEMENT TO. A Guide to Recent Lar-e Scale Maps,

including both Surveys and Compilations, together with a List of Some Large Sheetc-rrVî^^®^- ^y ^- Knox, M.A. Price .5s. 6d.

^

SWEDEN AND NORWAY. Handbook. 1901. Price Is. ed.

SWISS ARMY. Handbook. 1898. Price 6c;.

TACTICS. MODERN. Precis of. Orig-inally Compiled by Colonel

lb92 Pdce 4s"W?^^^^^ '^^'^sed and re-written by Lt.-Colonel Sisson Pratt.

^^±?^^. J^KOTECTORATE. Precis of Information concerning.1902. Price 5s. (kl.

VALPARAISO. The Capture of, in 1891. Report on. Price Is.

'^^Hcetf^^ ON A MAP, CONDUCT OF. Rules for the. 1899.

WAR ON LAND. LAWS AND CUSTOMS OF. Price 6d.

ZULULAND. Precis of Information concerning. With Map. 1894.Pnce 4s.

^

Manual of Military Engineering (1905)

Documents